1.创建vu3项目：

执行命令

npm create vue@latest

2.终端会出现如下选项，不确定的直接enter键进入下一步；

3.然后再执行下方命令：

cd <your-project-name>
npm install

4.安装依赖成功后引入elementui,执行命令：

npm install element-plus --save

5.引入element-plus分为全局引入和按需引入两种方式，一般在工程项目中，由于全局引入会导致不必要的资源加载，为提升项目性能，建议进行按需引入。两种引入方式分别为：

5.1全局引入：

全局引入就是在项目入口（main.ts）文件直接引入组件以及组件全部的样式文件；代码如下：

// main.ts
import { createApp } from 'vue'
import ElementPlus from 'element-plus' //全局引入
import 'element-plus/dist/index.css'
import App from './App.vue'

const app = createApp(App)

app.use(ElementPlus)
app.mount('#app')

5.2按需引入：

在vue3中按需引入ElementUI，需要使用其他的插件辅助，需要安装unplugin-vue-components 和 unplugin-auto-import这两款插件；执行如下命令：

npm install -D unplugin-vue-components unplugin-auto-import

然后再vite或者webpack或者vue.config.js配置中添加相应的配置，如下所示：

vite中

// vite.config.ts
import { defineConfig } from 'vite'
import AutoImport from 'unplugin-auto-import/vite'
import Components from 'unplugin-vue-components/vite'
import { ElementPlusResolver } from 'unplugin-vue-components/resolvers'

export default defineConfig({
  // ...
  plugins: [
    // ...
    AutoImport({
      resolvers: [ElementPlusResolver()],
    }),
    Components({
      resolvers: [ElementPlusResolver()],
    }),
  ],
})

webpack中

// webpack.config.js
const AutoImport = require('unplugin-auto-import/webpack')
const Components = require('unplugin-vue-components/webpack')
const { ElementPlusResolver } = require('unplugin-vue-components/resolvers')

module.exports = {
  // ...
  plugins: [
    AutoImport({
      resolvers: [ElementPlusResolver()],
    }),
    Components({
      resolvers: [ElementPlusResolver()],
    }),
  ],
}

vue.config.js中

const { defineConfig } = require('@vue/cli-service')
const AutoImport = require('unplugin-auto-import/webpack')
const Components = require('unplugin-vue-components/webpack')
const { ElementPlusResolver } = require('unplugin-vue-components/resolvers')

module.exports = defineConfig({
  configureWebpack: {
  	plugins: [
        AutoImport({
          resolvers: [ElementPlusResolver()],
        }),
        Components({
          resolvers: [ElementPlusResolver()],
        }),
      ],
  }
})

引入之后按需导入组件，如引入input组件和button组件：

<template>
  <div>
    <el-input class="input" v-model="input" type="file" placeholder="Please input" />
    <el-button class="button" type="primary">文件处理</el-button>
  </div>
</template>

<script>
  import { ElButton, ElInput } from 'element-plus'
  import { ref } from 'vue'
  
  export default {
    components: { ElButton,ElInput },
  }

</script>
<style scoped>
.input {
  display: inline;
  margin: 20px 30px;
}
.button {
  width: 90px;
}
</style>

6.运行项目命令：

npm run dev