1.修改模板

/src/layouts/BasicLayout.vue

添加如下代码

第一处：

  <!-- layout content -->
    <a-layout-content :style="{ height: '100%', margin: '0 0 40px 0', paddingTop: fixedHeader ? '64px' : '0' }">
      <multi-tab v-if="multiTab"></multi-tab>
      <transition name="page-transition">
      </transition>
    </a-layout-content>

第二处：

  // 多页标签
      multiTab: defaultSettings.multiTab,
      fixedHeader: defaultSettings.fixedHeader,

完整代码

<template>
  <pro-layout
    :menus="menus"
    :collapsed="collapsed"
    :mediaQuery="query"
    :isMobile="isMobile"
    :handleMediaQuery="handleMediaQuery"
    :handleCollapse="handleCollapse"
    :i18nRender="i18nRender"
    v-bind="settings"
  >
    <!-- Ads begin
      广告代码 真实项目中请移除
      production remove this Ads
    -->
    <ads v-if="isProPreviewSite && !collapsed"/>
    <!-- Ads end -->
    <!-- layout content -->
    <a-layout-content :style="{ height: '100%', margin: '0 0 40px 0', paddingTop: fixedHeader ? '64px' : '0' }">
      <multi-tab v-if="multiTab"></multi-tab>
      <transition name="page-transition">
      </transition>
    </a-layout-content>

    <!-- 1.0.0+ 版本 pro-layout 提供 API，
          我们推荐使用这种方式进行 LOGO 和 title 自定义
    -->
    <template v-slot:menuHeaderRender>
      <div>
        <logo-svg />
        <h1>{{ title }}</h1>
      </div>
    </template>
    <!-- 1.0.0+ 版本 pro-layout 提供 API,
          增加 Header 左侧内容区自定义
    -->
    <template v-slot:headerContentRender>
      <div>
        <a-tooltip title="刷新页面">
          <a-icon type="reload" style="font-size: 18px;cursor: pointer;" @click="() => { $message.info('只是一个DEMO') }" />
        </a-tooltip>
      </div>
    </template>

    <setting-drawer v-if="isDev" :settings="settings" @change="handleSettingChange">
      <div style="margin: 12px 0;">
        This is SettingDrawer custom footer content.
      </div>
    </setting-drawer>
    <template v-slot:rightContentRender>
      <right-content :top-menu="settings.layout === 'topmenu'" :is-mobile="isMobile" :theme="settings.theme" />
    </template>
    <!-- custom footer / 自定义Footer -->
    <template v-slot:footerRender>
      <global-footer />
    </template>
    <router-view />
  </pro-layout>
</template>

<script>
import { SettingDrawer, updateTheme } from '@ant-design-vue/pro-layout'
import { i18nRender } from '@/locales'
import { mapState } from 'vuex'
import { CONTENT_WIDTH_TYPE, SIDEBAR_TYPE, TOGGLE_MOBILE_TYPE } from '@/store/mutation-types'

import defaultSettings from '@/config/defaultSettings'
import RightContent from '@/components/GlobalHeader/RightContent'
import GlobalFooter from '@/components/GlobalFooter'
import Ads from '@/components/Other/CarbonAds'
import LogoSvg from '../assets/logo.svg?inline'

export default {
  name: 'BasicLayout',
  components: {
    SettingDrawer,
    RightContent,
    GlobalFooter,
    LogoSvg,
    Ads
  },
  data () {
    return {
      // preview.pro.antdv.com only use.
      isProPreviewSite: process.env.VUE_APP_PREVIEW === 'true' && process.env.NODE_ENV !== 'development',
      // end
      isDev: process.env.NODE_ENV === 'development' || process.env.VUE_APP_PREVIEW === 'true',
      // 多页标签
      multiTab: defaultSettings.multiTab,
      fixedHeader: defaultSettings.fixedHeader,
      // base
      menus: [],
      // 侧栏收起状态
      collapsed: false,
      title: defaultSettings.title,
      settings: {
        // 布局类型
        layout: defaultSettings.layout, // 'sidemenu', 'topmenu'
        // CONTENT_WIDTH_TYPE
        contentWidth: defaultSettings.layout === 'sidemenu' ? CONTENT_WIDTH_TYPE.Fluid : defaultSettings.contentWidth,
        // 主题 'dark' | 'light'
        theme: defaultSettings.navTheme,
        // 主色调
        primaryColor: defaultSettings.primaryColor,
        fixedHeader: defaultSettings.fixedHeader,
        fixSiderbar: defaultSettings.fixSiderbar,
        colorWeak: defaultSettings.colorWeak,

        hideHintAlert: false,
        hideCopyButton: false
      },
      // 媒体查询
      query: {},

      // 是否手机模式
      isMobile: false
    }
  },
  computed: {
    ...mapState({
      // 动态主路由
      mainMenu: state => state.permission.addRouters
    })
  },
  created () {
    const routes = this.mainMenu.find(item => item.path === '/')
    this.menus = (routes && routes.children) || []
    // 处理侧栏收起状态
    this.$watch('collapsed', () => {
      this.$store.commit(SIDEBAR_TYPE, this.collapsed)
    })
    this.$watch('isMobile', () => {
      this.$store.commit(TOGGLE_MOBILE_TYPE, this.isMobile)
    })
  },
  mounted () {
    const userAgent = navigator.userAgent
    if (userAgent.indexOf('Edge') > -1) {
      this.$nextTick(() => {
        this.collapsed = !this.collapsed
        setTimeout(() => {
          this.collapsed = !this.collapsed
        }, 16)
      })
    }

    // first update color
    // TIPS: THEME COLOR HANDLER!! PLEASE CHECK THAT!!
    if (process.env.NODE_ENV !== 'production' || process.env.VUE_APP_PREVIEW === 'true') {
      updateTheme(this.settings.primaryColor)
    }
  },
  methods: {
    i18nRender,
    handleMediaQuery (val) {
      this.query = val
      if (this.isMobile && !val['screen-xs']) {
        this.isMobile = false
        return
      }
      if (!this.isMobile && val['screen-xs']) {
        this.isMobile = true
        this.collapsed = false
        this.settings.contentWidth = CONTENT_WIDTH_TYPE.Fluid
        // this.settings.fixSiderbar = false
      }
    },
    handleCollapse (val) {
      this.collapsed = val
    },
    handleSettingChange ({ type, value }) {
      console.log('type', type, value)
      type && (this.settings[type] = value)
      switch (type) {
        case 'contentWidth':
          this.settings[type] = value
          break
        case 'layout':
          if (value === 'sidemenu') {
            this.settings.contentWidth = CONTENT_WIDTH_TYPE.Fluid
          } else {
            this.settings.fixSiderbar = false
            this.settings.contentWidth = CONTENT_WIDTH_TYPE.Fixed
          }
          break
      }
    }
  }
}
</script>

<style lang="less">
@import "./BasicLayout.less";
</style>

2.修改默认配置

/src/config/defaultSettings.js

添加如下代码

 multiTab: true,

完整代码：

/**
 * 项目默认配置项
 * primaryColor - 默认主题色, 如果修改颜色不生效，请清理 localStorage
 * navTheme - sidebar theme ['dark', 'light'] 两种主题
 * colorWeak - 色盲模式
 * layout - 整体布局方式 ['sidemenu', 'topmenu'] 两种布局
 * fixedHeader - 固定 Header : boolean
 * fixSiderbar - 固定左侧菜单栏 ： boolean
 * contentWidth - 内容区布局： 流式 |  固定
 *
 * storageOptions: {} - Vue-ls 插件配置项 (localStorage/sessionStorage)
 *
 */

export default {
  navTheme: 'dark', // theme for nav menu
  primaryColor: '#1890ff', // '#F5222D', // primary color of ant design
  layout: 'sidemenu', // nav menu position: `sidemenu` or `topmenu`
  contentWidth: 'Fluid', // layout of content: `Fluid` or `Fixed`, only works when layout is topmenu
  fixedHeader: false, // sticky header
  fixSiderbar: false, // sticky siderbar
  colorWeak: false,
  multiTab: true,
  menu: {
    locale: true
  },
  title: 'Ant Design Pro',
  pwa: false,
  iconfontUrl: '',
  production: process.env.NODE_ENV === 'production' && process.env.VUE_APP_PREVIEW !== 'true'
}

3. 效果