<el-submenu :index="item.id+''" v-for="(item,index) in menuList" :key="item.id">
<template slot="title">
  <i :class="icons[index]"></i>
  <span>{{item.authName}}</span>
</template>

data() {
    return {
      icons: ['el-icon-s-custom', 'el-icon-s-claim', 'el-icon-s-goods', 'el-icon-s-order', 'el-icon-s-data']
    }

v-for="(item,index) in menuList"