getChildrenList (fid, level = 0) {
 return new Promise((resolve, reject) => {
 API.getCategory({ fid: fid, level: level }).then(
  res => {
  if (res) {
  if (res.code === 0 && res.result) {
  resolve(res.result)
  }
  }
  }
 )
 })
 },
let twolist = this.getChildrenList(codeArr[0], 1)
let thirdlist = this.getChildrenList(codeArr[1], 2)
Promise.all([twolist, thirdlist]).then((data) => {
 ...
})

<template>
 <div>
 <el-cascader
 placeholder="请选择所属类目"
 :options="categoryList"
 :show-all-levels="false"
 v-model="category"
 collapse-tags
 :props="{
 multiple: true,
 value: 'code',
 label: 'name',
 children: 'children',
 ...props,
 }"
 />
 <el-cascader
 placeholder="请选择所属类目"
 :options="secondCategoryList"
 :show-all-levels="false"
 v-model="secondCategory"
 collapse-tags
 :props="{
 multiple: true,
 value: 'code',
 label: 'name',
 children: 'children',
 ...props,
 }"
 />
 </div>
</template>
 
<script>
export default {
 data () {
 return {
 categoryList: [],
 category: [],
 secondCategoryList: [],
 secondCategory: [],
 props: {
 lazy: true,
 // checkStrictly: true, // 父子级节点关联
 async lazyLoad (node, reso) {
  const { level, data } = node
  if (data && data.children && data.children.length !== 0) {
  return reso(node)
  }
  if (data && data.leaf) {
  return reso([])
  }
  const lv3Code = data "less" scoped> 
</style>

import React from 'react';
import {Button, Form, message, Row, Tag,Select,Col} from 'antd';
import request from "../../../../utils/request";
const FormItem = Form.Item;
const Option = Select.Option;
 
class CarSeriesCascader extends React.Component {
 
 constructor(props) {
  super(props);
  this.state = {
   defaultBrandList:[],
   selectedCarModelList: props.carModelList "获取品牌数据失败");
  }
  }).catch(err => {
   message.error("获取品牌数据失败");
  });
  // this.setState({
  // selectedCarModelList:(this.props.carModelList "车型已在已选车型中");
     return;
    }
   }
   addCarModel.carId = this.state.carId;
   addCarModel.modelCode = this.state.modelCode;
   addCarModel.modelName = this.state.modelName;
   selectedCarModelList.push(addCarModel);
  } else {
   return;
  }
  this.handleChange(selectedCarModelList);
  this.setState({
   selectedCarModelList
  });
 }
 
 handleChange = (selectedCarModelList) => {
  if (this.props.onChange) {
   let limitList = this.getLimitList(selectedCarModelList);
   this.props.onChange(limitList);
  }
 }
 
 deleteTag = (limitCode) => {
  debugger
  let selectedCarModelList = this.state.selectedCarModelList;
  selectedCarModelList = selectedCarModelList.filter(carModel => !(carModel.modelCode === limitCode));
  this.handleChange(selectedCarModelList);
  this.setState({selectedCarModelList});
 }
 
 //品牌变化
 brandChange = (brandName) => {
 this.state.defaultBrandList.map((item, index) => {
  if (item.brandName == brandName) {
  let promise = request(`/car/getModelList"获取车型数据失败");
   }
  }).catch(err => {
   message.error("获取车型数据失败:");
  });
  }
 });
 }
 
 //车型变化
 modelChange = (modelName) => {
 this.props.form.setFieldsValue({modelName: null});
 let _this = this;
 this.state.carModelList.map((item, index) => {
  if (item.modelName == modelName) {
  console.log(item);
  this.setState({
  modelCode : item.modelCode,
  carId : item.carId,
  modelName : item.modelName
  });
  }
 });
 }
 
 render() {
  const {getFieldDecorator} = this.props.form;
  //品牌名称列表
  let allBrandListOption = this.state.defaultBrandList != null "品牌"
       dropdownMatchSelectWidth={false}
       onChange={this.brandChange}
       style={{ marginRight: 10, width: 100 }}>
       <Option value={null}>选择品牌</Option>
       {allBrandListOption}
      </Select>
      )}
      {getFieldDecorator('modelName', {
      rules: [{
       message: '请选择车型'
      }],
      })(
      <Select
       placeholder="车型"
       dropdownMatchSelectWidth={false}
       onChange={this.modelChange}
       style={{ marginRight: 10, width: 260 }}>
       <Option value={null}>选择车型</Option>
       {allModelListOption}
      </Select>
      )}
      <Button type={"primary"} icon={"plus"} onClick={this.addCarModel}>添加车型</Button>
     </FormItem>
    </Row>
    <Row>
     {existCarModel}
    </Row>
   </div>
  )
 }
} 
export default Form.create()(CarSeriesCascader);