It seems it can be fixed in vue-loader , replacing api.install(require('vue') by

import Vue from 'vue' 
api.install(Vue)

then webpack can know when 'vue' is used and await Promise of the script before using it.

@fangbinwei It works fine if serve static files after npm run build. Is there something wrong in vue-cli-service?

Some HMR codes use 'vue' by require('vue') which return Promise because of externalsType. HMR codes is injected only in dev mode, so it's no problem in production. @Urie96

Using externalsType: 'script', require('vue') return Promise

require('vue').then(Vue => {
  new Vue({})
})

if use vue like below, webpack will transform codes and handle the Promise automatically

import Vue from 'vue'
new Vue({})

@fangbinwei 谢谢解答，你上面讲的我配置不了哒，所以是要等待新的发布哇

是的, 现在只能先这样

/** @type {import('@vue/cli-service').ProjectOptions} */
module.exports = {
  configureWebpack: (config) => {
    if (process.env.NODE_ENV === 'production') {
      return {
        externalsType: 'script',
        externals: {
          vue: ['https://cdn.jsdelivr.net/npm/vue@2.6.12/dist/vue.min.js', 'Vue']
        }
      }
    }
  }
}