需求：手机号的input框默认一个，点击加号，可以增加和减少。

<template>
  <el-form :model="editUserForm" label-width="80px" hide-required-asterisk ref="editUserFormRef">
      <!-- 手机 -->
      <el-form-item label="手机号：" :prop="'mobiles.0.value'" >
        <el-input
          v-model="editUserForm.mobiles[0].value"
          placeholder="请输入手机号"
          clearable
        ></el-input>
        <el-button @click.prevent="addMobile">+</el-button>
      </el-form-item>
      <el-form-item
      v-for="(mobile, index) in editUserForm.mobiles.slice(1)"
        :key="mobile.key"
        :prop="'mobiles.' + (index + 1) + '.value'"
      >
        <el-input
          v-model="mobile.value"
          placeholder="请输入手机号"
          clearable
        ></el-input>
        <el-button class="remove-button" @click.prevent="removeMobile(mobile)">-</el-button>
      </el-form-item>
    </el-form>
</template>

<script setup lang='ts'>
import { onMounted,reactive } from 'vue';


//表单的数据
const editUserForm = reactive({
  mobiles: [
    {
      value: '1782731823',
      key:1
    },
    {
      value: '777777777',
      key:3
    },
  ]
})

//删除input
const removeMobile = (item): void => {
  const index = editUserForm.mobiles.indexOf(item)
  if (index !== -1) {
    editUserForm.mobiles.splice(index, 1)
  }
}
//增加input
const addMobile = (): void => {
  if (editUserForm.mobiles.length < 10) {
    editUserForm.mobiles.push({
      value: '',
      key: Date.now(),
    })
  } else {
    console.log('手机号增加数量已上限！')
  }
}
</script>

<style lang='scss' scoped></style>

通过 对数据的增减而增加和减少input框，而不是操作dom

效果图如下：