可以用復選框模擬單選按鈕

<template>
  <el-checkbox-group v-model="checkedCities">
    <el-checkbox v-for="(city,index) in cities" :label="city" :key="city" @change='hanChange(city,index)'>{{city}}</el-checkbox>
  </el-checkbox-group>
</template>

data() {
  return {
    checkedCities: ['上海'],
    cities: ['上海', '北京', '廣州', '深圳']
  };
},
methods: {
  hanChange(city,index) {
      this.checkedCities = this.checkedCities.includes(city)?[city]:[]
  }
}

額，你這個問題有點模糊啊。單元按鈕不就是點一下選中再點消失嗎

<div :class"={selected:selectIndex}" @click="selectIndex=!selectIndex"></div>

簡化點這么寫了。selectIndex默認為true就是選中，給這個類名寫對應的選中樣式