SOURCE

var vm = new Vue({
    el: '#app',
    data() {
        return {
        }
    }
})

<!-- 引入element-ui样式 -->
<link rel="stylesheet" href="https://unpkg.com/element-ui/lib/theme-chalk/index.css">
<!-- 引入vue -->
<script src="https://cdn.bootcdn.net/ajax/libs/vue/2.6.11/vue.min.js"></script>
<!-- 引入element-ui组件库 -->
<script src="https://unpkg.com/element-ui/lib/index.js"></script>

<div id="app">
  <el-button>111</el-button>
</div>