diff --git a/.env.development b/.env.development
index 8f5856db..de583d09 100644
--- a/.env.development
+++ b/.env.development
@@ -3,12 +3,3 @@ ENV = 'development'
 
 # base api
 VUE_APP_BASE_API = '/dev-api'
-
-# vue-cli uses the VUE_CLI_BABEL_TRANSPILE_MODULES environment variable,
-# to control whether the babel-plugin-dynamic-import-node plugin is enabled.
-# It only does one thing by converting all import() to require().
-# This configuration can significantly increase the speed of hot updates,
-# when you have a large number of pages.
-# Detail:  https://github.com/vuejs/vue-cli/blob/dev/packages/@vue/babel-preset-app/index.js
-
-VUE_CLI_BABEL_TRANSPILE_MODULES = true
diff --git a/babel.config.js b/babel.config.js
index ba179669..fb82b271 100644
--- a/babel.config.js
+++ b/babel.config.js
@@ -1,5 +1,14 @@
 module.exports = {
   presets: [
-    '@vue/app'
-  ]
+    // https://github.com/vuejs/vue-cli/tree/master/packages/@vue/babel-preset-app
+    '@vue/cli-plugin-babel/preset'
+  ],
+  'env': {
+    'development': {
+      // babel-plugin-dynamic-import-node plugin only does one thing by converting all import() to require().
+      // This plugin can significantly increase the speed of hot updates, when you have a large number of pages.
+      // https://panjiachen.github.io/vue-element-admin-site/guide/advanced/lazy-loading.html
+      'plugins': ['dynamic-import-node']
+    }
+  }
 }
diff --git a/mock/article.js b/mock/article.js
index 50218ae4..23d8ba51 100644
--- a/mock/article.js
+++ b/mock/article.js
@@ -1,4 +1,4 @@
-import Mock from 'mockjs'
+const Mock = require('mockjs')
 
 const List = []
 const count = 100
@@ -27,7 +27,7 @@ for (let i = 0; i < count; i++) {
   }))
 }
 
-export default [
+module.exports = [
   {
     url: '/vue-element-admin/article/list',
     type: 'get',
diff --git a/mock/index.js b/mock/index.js
index 196e2927..2eed65db 100644
--- a/mock/index.js
+++ b/mock/index.js
@@ -1,10 +1,10 @@
-import Mock from 'mockjs'
-import { param2Obj } from '../src/utils'
+const Mock = require('mockjs')
+const { param2Obj } = require('./utils')
 
-import user from './user'
-import role from './role'
-import article from './article'
-import search from './remote-search'
+const user = require('./user')
+const role = require('./role')
+const article = require('./article')
+const search = require('./remote-search')
 
 const mocks = [
   ...user,
@@ -16,7 +16,7 @@ const mocks = [
 // for front mock
 // please use it cautiously, it will redefine XMLHttpRequest,
 // which will cause many of your third-party libraries to be invalidated(like progress event).
-export function mockXHR() {
+function mockXHR() {
   // mock patch
   // https://github.com/nuysoft/Mock/issues/300
   Mock.XHR.prototype.proxy_send = Mock.XHR.prototype.send
@@ -54,4 +54,7 @@ export function mockXHR() {
   }
 }
 
-export default mocks
+module.exports = {
+  mocks,
+  mockXHR
+}
diff --git a/mock/mock-server.js b/mock/mock-server.js
index 806fdacc..8941ec0f 100644
--- a/mock/mock-server.js
+++ b/mock/mock-server.js
@@ -8,7 +8,7 @@ const mockDir = path.join(process.cwd(), 'mock')
 
 function registerRoutes(app) {
   let mockLastIndex
-  const { default: mocks } = require('./index.js')
+  const { mocks } = require('./index.js')
   const mocksForServer = mocks.map(route => {
     return responseFake(route.url, route.type, route.response)
   })
@@ -44,9 +44,6 @@ const responseFake = (url, type, respond) => {
 }
 
 module.exports = app => {
-  // es6 polyfill
-  require('@babel/register')
-
   // parse app.body
   // https://expressjs.com/en/4x/api.html#req.body
   app.use(bodyParser.json())
diff --git a/mock/remote-search.js b/mock/remote-search.js
index 60809cb8..8fc49267 100644
--- a/mock/remote-search.js
+++ b/mock/remote-search.js
@@ -1,4 +1,4 @@
-import Mock from 'mockjs'
+const Mock = require('mockjs')
 
 const NameList = []
 const count = 100
@@ -10,7 +10,7 @@ for (let i = 0; i < count; i++) {
 }
 NameList.push({ name: 'mock-Pan' })
 
-export default [
+module.exports = [
   // username search
   {
     url: '/vue-element-admin/search/user',
diff --git a/mock/role/index.js b/mock/role/index.js
index d957493b..4643f006 100644
--- a/mock/role/index.js
+++ b/mock/role/index.js
@@ -1,6 +1,6 @@
-import Mock from 'mockjs'
-import { deepClone } from '../../src/utils/index.js'
-import { asyncRoutes, constantRoutes } from './routes.js'
+const Mock = require('mockjs')
+const { deepClone } = require('../utils')
+const { asyncRoutes, constantRoutes } = require('./routes.js')
 
 const routes = deepClone([...constantRoutes, ...asyncRoutes])
 
@@ -35,7 +35,7 @@ const roles = [
   }
 ]
 
-export default [
+module.exports = [
   // mock get all routes form server
   {
     url: '/vue-element-admin/routes',
diff --git a/mock/role/routes.js b/mock/role/routes.js
index c4654566..757aa38b 100644
--- a/mock/role/routes.js
+++ b/mock/role/routes.js
@@ -1,6 +1,6 @@
 // Just a mock data
 
-export const constantRoutes = [
+const constantRoutes = [
   {
     path: '/redirect',
     component: 'layout/Layout',
@@ -72,7 +72,7 @@ export const constantRoutes = [
   }
 ]
 
-export const asyncRoutes = [
+const asyncRoutes = [
   {
     path: '/permission',
     component: 'layout/Layout',
@@ -523,3 +523,8 @@ export const asyncRoutes = [
 
   { path: '*', redirect: '/404', hidden: true }
 ]
+
+module.exports = {
+  constantRoutes,
+  asyncRoutes
+}
diff --git a/mock/user.js b/mock/user.js
index 859bd6f3..d82e079d 100644
--- a/mock/user.js
+++ b/mock/user.js
@@ -23,7 +23,7 @@ const users = {
   }
 }
 
-export default [
+module.exports = [
   // user login
   {
     url: '/vue-element-admin/user/login',
diff --git a/mock/utils.js b/mock/utils.js
new file mode 100644
index 00000000..f909a293
--- /dev/null
+++ b/mock/utils.js
@@ -0,0 +1,48 @@
+/**
+ * @param {string} url
+ * @returns {Object}
+ */
+function param2Obj(url) {
+  const search = decodeURIComponent(url.split('?')[1]).replace(/\+/g, ' ')
+  if (!search) {
+    return {}
+  }
+  const obj = {}
+  const searchArr = search.split('&')
+  searchArr.forEach(v => {
+    const index = v.indexOf('=')
+    if (index !== -1) {
+      const name = v.substring(0, index)
+      const val = v.substring(index + 1, v.length)
+      obj[name] = val
+    }
+  })
+  return obj
+}
+
+/**
+ * This is just a simple version of deep copy
+ * Has a lot of edge cases bug
+ * If you want to use a perfect deep copy, use lodash's _.cloneDeep
+ * @param {Object} source
+ * @returns {Object}
+ */
+function deepClone(source) {
+  if (!source && typeof source !== 'object') {
+    throw new Error('error arguments', 'deepClone')
+  }
+  const targetObj = source.constructor === Array ? [] : {}
+  Object.keys(source).forEach(keys => {
+    if (source[keys] && typeof source[keys] === 'object') {
+      targetObj[keys] = deepClone(source[keys])
+    } else {
+      targetObj[keys] = source[keys]
+    }
+  })
+  return targetObj
+}
+
+module.exports = {
+  param2Obj,
+  deepClone
+}
diff --git a/package.json b/package.json
index c829a00d..70b3aba0 100644
--- a/package.json
+++ b/package.json
@@ -1,56 +1,29 @@
 {
   "name": "vue-element-admin",
-  "version": "4.3.0",
+  "version": "4.3.1",
   "description": "A magical vue admin. An out-of-box UI solution for enterprise applications. Newest development stack of vue. Lots of awesome features",
   "author": "Pan <panfree23@gmail.com>",
-  "license": "MIT",
   "scripts": {
     "dev": "vue-cli-service serve",
+    "lint": "eslint --ext .js,.vue src",
     "build:prod": "vue-cli-service build",
     "build:stage": "vue-cli-service build --mode staging",
     "preview": "node build/index.js --preview",
-    "lint": "eslint --ext .js,.vue src",
+    "new": "plop",
+    "svgo": "svgo -f src/icons/svg --config=src/icons/svgo.yml",
     "test:unit": "jest --clearCache && vue-cli-service test:unit",
     "test:ci": "npm run lint && npm run test:unit",
-    "svgo": "svgo -f src/icons/svg --config=src/icons/svgo.yml",
-    "new": "plop",
     "deploy": "bash deploy.sh"
   },
-  "husky": {
-    "hooks": {
-      "pre-commit": "lint-staged"
-    }
-  },
-  "lint-staged": {
-    "src/**/*.{js,vue}": [
-      "eslint --fix",
-      "git add"
-    ]
-  },
-  "keywords": [
-    "vue",
-    "admin",
-    "dashboard",
-    "element-ui",
-    "boilerplate",
-    "admin-template",
-    "management-system"
-  ],
-  "repository": {
-    "type": "git",
-    "url": "git+https://github.com/PanJiaChen/vue-element-admin.git"
-  },
-  "bugs": {
-    "url": "https://github.com/PanJiaChen/vue-element-admin/issues"
-  },
   "dependencies": {
     "axios": "0.18.1",
     "clipboard": "2.0.4",
     "codemirror": "5.45.0",
+    "core-js": "3.6.5",
     "driver.js": "0.9.5",
     "dropzone": "5.5.1",
     "echarts": "4.2.1",
-    "element-ui": "2.13.0",
+    "element-ui": "2.13.2",
     "file-saver": "2.0.1",
     "fuse.js": "3.4.4",
     "js-cookie": "2.2.0",
@@ -62,7 +35,6 @@
     "pinyin": "2.9.0",
     "screenfull": "4.2.0",
     "script-loader": "0.7.2",
-    "showdown": "1.9.0",
     "sortablejs": "1.8.4",
     "tui-editor": "1.3.3",
     "vue": "2.6.10",
@@ -76,42 +48,68 @@
     "xlsx": "0.14.1"
   },
   "devDependencies": {
-    "@babel/core": "7.0.0",
-    "@babel/register": "7.0.0",
-    "@vue/cli-plugin-babel": "3.5.3",
-    "@vue/cli-plugin-eslint": "^3.9.1",
-    "@vue/cli-plugin-unit-jest": "3.5.3",
-    "@vue/cli-service": "3.5.3",
+    "@vue/cli-plugin-babel": "4.4.4",
+    "@vue/cli-plugin-eslint": "4.4.4",
+    "@vue/cli-plugin-unit-jest": "4.4.4",
+    "@vue/cli-service": "4.4.4",
     "@vue/test-utils": "1.0.0-beta.29",
-    "autoprefixer": "^9.5.1",
-    "babel-core": "7.0.0-bridge.0",
-    "babel-eslint": "10.0.1",
+    "autoprefixer": "9.5.1",
+    "babel-eslint": "10.1.0",
     "babel-jest": "23.6.0",
+    "babel-plugin-dynamic-import-node": "2.3.3",
     "chalk": "2.4.2",
     "chokidar": "2.1.5",
     "connect": "3.6.6",
-    "eslint": "5.15.3",
-    "eslint-plugin-vue": "5.2.2",
+    "eslint": "6.7.2",
+    "eslint-plugin-vue": "6.2.2",
     "html-webpack-plugin": "3.2.0",
     "husky": "1.3.1",
     "lint-staged": "8.1.5",
     "mockjs": "1.0.1-beta3",
     "plop": "2.3.0",
-    "runjs": "^4.3.2",
-    "sass": "^1.26.2",
-    "sass-loader": "^7.1.0",
+    "runjs": "4.3.2",
+    "sass": "1.26.2",
+    "sass-loader": "8.0.2",
     "script-ext-html-webpack-plugin": "2.1.3",
-    "serve-static": "^1.13.2",
+    "serve-static": "1.13.2",
     "svg-sprite-loader": "4.1.3",
     "svgo": "1.2.0",
     "vue-template-compiler": "2.6.10"
   },
+  "browserslist": [
+    "> 1%",
+    "last 2 versions"
+  ],
+  "bugs": {
+    "url": "https://github.com/PanJiaChen/vue-element-admin/issues"
+  },
   "engines": {
     "node": ">=8.9",
     "npm": ">= 3.0.0"
   },
-  "browserslist": [
-    "> 1%",
-    "last 2 versions"
-  ]
+  "keywords": [
+    "vue",
+    "admin",
+    "dashboard",
+    "element-ui",
+    "boilerplate",
+    "admin-template",
+    "management-system"
+  ],
+  "license": "MIT",
+  "lint-staged": {
+    "src/**/*.{js,vue}": [
+      "eslint --fix",
+      "git add"
+    ]
+  },
+  "husky": {
+    "hooks": {
+      "pre-commit": "lint-staged"
+    }
+  },
+  "repository": {
+    "type": "git",
+    "url": "git+https://github.com/PanJiaChen/vue-element-admin.git"
+  }
 }
diff --git a/plop-templates/utils.js b/plop-templates/utils.js
index 0310ca02..04987539 100644
--- a/plop-templates/utils.js
+++ b/plop-templates/utils.js
@@ -1,9 +1,2 @@
-exports.notEmpty = name => {
-  return v => {
-    if (!v || v.trim === '') {
-      return `${name} is required`
-    } else {
-      return true
-    }
-  }
-}
+exports.notEmpty = name => v =>
+  !v || v.trim() === '' ? `${name} is required` : true
diff --git a/src/components/ImageCropper/index.vue b/src/components/ImageCropper/index.vue
index 13ae9a11..65a4262b 100644
--- a/src/components/ImageCropper/index.vue
+++ b/src/components/ImageCropper/index.vue
@@ -248,6 +248,7 @@ export default {
       // 浏览器是否支持该控件
       isSupported,
       // 浏览器是否支持触屏事件
+      // eslint-disable-next-line no-prototype-builtins
       isSupportTouch: document.hasOwnProperty('ontouchstart'),
       // 步骤
       step: 1, // 1选择文件 2剪裁 3上传
diff --git a/src/directive/permission/permission.js b/src/directive/permission/permission.js
index b27f24da..49d1f889 100644
--- a/src/directive/permission/permission.js
+++ b/src/directive/permission/permission.js
@@ -1,11 +1,11 @@
 import store from '@/store'
 
-export default {
-  inserted(el, binding, vnode) {
-    const { value } = binding
-    const roles = store.getters && store.getters.roles
+function checkPermission(el, binding) {
+  const { value } = binding
+  const roles = store.getters && store.getters.roles
 
-    if (value && value instanceof Array && value.length > 0) {
+  if (value && value instanceof Array) {
+    if (value.length > 0) {
       const permissionRoles = value
 
       const hasPermission = roles.some(role => {
@@ -15,8 +15,17 @@ export default {
       if (!hasPermission) {
         el.parentNode && el.parentNode.removeChild(el)
       }
-    } else {
-      throw new Error(`need roles! Like v-permission="['admin','editor']"`)
     }
+  } else {
+    throw new Error(`need roles! Like v-permission="['admin','editor']"`)
+  }
+}
+
+export default {
+  inserted(el, binding) {
+    checkPermission(el, binding)
+  },
+  update(el, binding) {
+    checkPermission(el, binding)
   }
 }
diff --git a/src/layout/components/Sidebar/Item.vue b/src/layout/components/Sidebar/Item.vue
index b515f615..aa1f5da4 100644
--- a/src/layout/components/Sidebar/Item.vue
+++ b/src/layout/components/Sidebar/Item.vue
@@ -17,7 +17,11 @@ export default {
     const vnodes = []
 
     if (icon) {
-      vnodes.push(<svg-icon icon-class={icon}/>)
+      if (icon.includes('el-icon')) {
+        vnodes.push(<i class={[icon, 'sub-el-icon']} />)
+      } else {
+        vnodes.push(<svg-icon icon-class={icon}/>)
+      }
     }
 
     if (title) {
@@ -27,3 +31,11 @@ export default {
   }
 }
 </script>
+
+<style scoped>
+.sub-el-icon {
+  color: currentColor;
+  width: 1em;
+  height: 1em;
+}
+</style>
diff --git a/src/router/index.js b/src/router/index.js
index f6151ec6..dec899ea 100644
--- a/src/router/index.js
+++ b/src/router/index.js
@@ -25,7 +25,7 @@ import nestedRouter from './modules/nested'
  * meta : {
     roles: ['admin','editor']    control the page roles (you can set multiple roles)
     title: 'title'               the name show in sidebar and breadcrumb (recommend set)
-    icon: 'svg-name'             the icon show in the sidebar
+    icon: 'svg-name'/'el-icon-x' the icon show in the sidebar
     noCache: true                if set true, the page will no be cached(default is false)
     affix: true                  if set true, the tag will affix in the tags-view
     breadcrumb: false            if set false, the item will hidden in breadcrumb(default is true)
@@ -197,7 +197,7 @@ export const asyncRoutes = [
     name: 'Example',
     meta: {
       title: 'example',
-      icon: 'example'
+      icon: 'el-icon-s-help'
     },
     children: [
       {
diff --git a/src/store/modules/settings.js b/src/store/modules/settings.js
index e638a4c4..640368cd 100644
--- a/src/store/modules/settings.js
+++ b/src/store/modules/settings.js
@@ -14,6 +14,7 @@ const state = {
 
 const mutations = {
   CHANGE_SETTING: (state, { key, value }) => {
+    // eslint-disable-next-line no-prototype-builtins
     if (state.hasOwnProperty(key)) {
       state[key] = value
     }
diff --git a/src/store/modules/user.js b/src/store/modules/user.js
index 1391fa4a..78009412 100644
--- a/src/store/modules/user.js
+++ b/src/store/modules/user.js
@@ -103,28 +103,23 @@ const actions = {
   },
 
   // dynamically modify permissions
-  changeRoles({ commit, dispatch }, role) {
-    return new Promise(async resolve => {
-      const token = role + '-token'
+  async changeRoles({ commit, dispatch }, role) {
+    const token = role + '-token'
 
-      commit('SET_TOKEN', token)
-      setToken(token)
+    commit('SET_TOKEN', token)
+    setToken(token)
 
-      const { roles } = await dispatch('getInfo')
+    const { roles } = await dispatch('getInfo')
 
-      resetRouter()
+    resetRouter()
 
-      // generate accessible routes map based on roles
-      const accessRoutes = await dispatch('permission/generateRoutes', roles, { root: true })
+    // generate accessible routes map based on roles
+    const accessRoutes = await dispatch('permission/generateRoutes', roles, { root: true })
+    // dynamically add accessible routes
+    router.addRoutes(accessRoutes)
 
-      // dynamically add accessible routes
-      router.addRoutes(accessRoutes)
-
-      // reset visited views and cached views
-      dispatch('tagsView/delAllViews', null, { root: true })
-
-      resolve()
-    })
+    // reset visited views and cached views
+    dispatch('tagsView/delAllViews', null, { root: true })
   }
 }
 
diff --git a/src/styles/sidebar.scss b/src/styles/sidebar.scss
index 3dad4c39..94760cc7 100644
--- a/src/styles/sidebar.scss
+++ b/src/styles/sidebar.scss
@@ -57,6 +57,11 @@
       margin-right: 16px;
     }
 
+    .sub-el-icon {
+      margin-right: 12px;
+      margin-left: -2px;
+    }
+
     .el-menu {
       border: none;
       height: 100%;
@@ -105,6 +110,10 @@
         .svg-icon {
           margin-left: 20px;
         }
+
+        .sub-el-icon {
+          margin-left: 19px;
+        }
       }
     }
 
@@ -118,6 +127,10 @@
           margin-left: 20px;
         }
 
+        .sub-el-icon {
+          margin-left: 19px;
+        }
+
         .el-submenu__icon-arrow {
           display: none;
         }
@@ -178,6 +191,10 @@
     .svg-icon {
       margin-right: 16px;
     }
+    .sub-el-icon {
+      margin-right: 12px;
+      margin-left: -2px;
+    }
   }
 
   .nest-menu .el-submenu>.el-submenu__title,
diff --git a/src/utils/index.js b/src/utils/index.js
index 96ee6e7f..3225d3c4 100644
--- a/src/utils/index.js
+++ b/src/utils/index.js
@@ -162,19 +162,21 @@ export function param(json) {
  * @returns {Object}
  */
 export function param2Obj(url) {
-  const search = url.split('?')[1]
+  const search = decodeURIComponent(url.split('?')[1]).replace(/\+/g, ' ')
   if (!search) {
     return {}
   }
-  return JSON.parse(
-    '{"' +
-      decodeURIComponent(search)
-        .replace(/"/g, '\\"')
-        .replace(/&/g, '","')
-        .replace(/=/g, '":"')
-        .replace(/\+/g, ' ') +
-      '"}'
-  )
+  const obj = {}
+  const searchArr = search.split('&')
+  searchArr.forEach(v => {
+    const index = v.indexOf('=')
+    if (index !== -1) {
+      const name = v.substring(0, index)
+      const val = v.substring(index + 1, v.length)
+      obj[name] = val
+    }
+  })
+  return obj
 }
 
 /**
diff --git a/src/views/excel/merge-header.vue b/src/views/excel/merge-header.vue
index 2646b9d0..4be0227d 100644
--- a/src/views/excel/merge-header.vue
+++ b/src/views/excel/merge-header.vue
@@ -71,21 +71,21 @@ export default {
     },
     handleDownload() {
       this.downloadLoading = true
-        import('@/vendor/Export2Excel').then(excel => {
-          const multiHeader = [['Id', 'Main Information', '', '', 'Date']]
-          const header = ['', 'Title', 'Author', 'Readings', '']
-          const filterVal = ['id', 'title', 'author', 'pageviews', 'display_time']
-          const list = this.list
-          const data = this.formatJson(filterVal, list)
-          const merges = ['A1:A2', 'B1:D1', 'E1:E2']
-          excel.export_json_to_excel({
-            multiHeader,
-            header,
-            merges,
-            data
-          })
-          this.downloadLoading = false
+      import('@/vendor/Export2Excel').then(excel => {
+        const multiHeader = [['Id', 'Main Information', '', '', 'Date']]
+        const header = ['', 'Title', 'Author', 'Readings', '']
+        const filterVal = ['id', 'title', 'author', 'pageviews', 'display_time']
+        const list = this.list
+        const data = this.formatJson(filterVal, list)
+        const merges = ['A1:A2', 'B1:D1', 'E1:E2']
+        excel.export_json_to_excel({
+          multiHeader,
+          header,
+          merges,
+          data
         })
+        this.downloadLoading = false
+      })
     },
     formatJson(filterVal, jsonData) {
       return jsonData.map(v => filterVal.map(j => {
diff --git a/tests/unit/utils/param2Obj.spec.js b/tests/unit/utils/param2Obj.spec.js
new file mode 100644
index 00000000..e106ed88
--- /dev/null
+++ b/tests/unit/utils/param2Obj.spec.js
@@ -0,0 +1,14 @@
+import { param2Obj } from '@/utils/index.js'
+describe('Utils:param2Obj', () => {
+  const url = 'https://github.com/PanJiaChen/vue-element-admin?name=bill&age=29&sex=1&field=dGVzdA==&key=%E6%B5%8B%E8%AF%95'
+
+  it('param2Obj test', () => {
+    expect(param2Obj(url)).toEqual({
+      name: 'bill',
+      age: '29',
+      sex: '1',
+      field: window.btoa('test'),
+      key: '测试'
+    })
+  })
+})
diff --git a/vue.config.js b/vue.config.js
index 4a58a00b..386a776c 100644
--- a/vue.config.js
+++ b/vue.config.js
@@ -49,8 +49,11 @@ module.exports = {
     }
   },
   chainWebpack(config) {
-    config.plugins.delete('preload') // TODO: need test
-    config.plugins.delete('prefetch') // TODO: need test
+    // it can improve the speed of the first screen, it is recommended to turn on preload
+    // config.plugins.delete('preload')
+
+    // when there are many pages, it will cause too many meaningless requests
+    config.plugins.delete('prefetch')
 
     // set svg-sprite-loader
     config.module