<div v-for="(item,index) in 10"
      :key="index">{{item}}</div>
    <div v-for="(item,index) in 10"
      :key="index">{{item}}</div>

处于同级的div若用v-for时需要谨慎，展开后每个div的key都要相异 vue3这种情况不会报错

解决方案

<div v-for="(item,index) in 10"
  :key="index">{{item}}</div>
<div v-for="(item,index) in 10"
  :key="index+'arr2'">{{item}}</div>