方法一：
代码实现：

<el-row type="flex" class="row-bg">
                <el-col :span="11" :offset="0" >
                    <el-form-item label="地点" prop="warrantName" label-width="150px">
                        <el-checkbox-group v-model="warrantName">
                            <el-checkbox v-for="city in cities" @change="warrantNameChange" :label="city" :key="city">{{city}}</el-checkbox>
                        </el-checkbox-group>
                    </el-form-item>
                </el-col>
            </el-row>

 const cityOptions = ['上海', '北京', '广州', '深圳'];
 return {
                warrantName:[],
                cities: cityOptions,
                //表单定义
                addForm:{
                    "warrantName":"",
                },
            }
 methods: {
 //当绑定值变化时触发的事件
warrantNameChange(){
//把多选框的数组转化成字符串传给addFrom表单
this.addForm.warrantName = this.warrantName.join(",");
            },          

方法二：就是把单独多选框的数组值传到后台处理，那样太麻烦了，就不展示了