<picker
 mode="multiSelector"
 bindchange="bindjobcatchange"
 bindcolumnchange="bingjobcatcolumnchange"
 value="{{multiIndex}}"
 range="{{job_cat_list}}"
  range-key="{{'cat_name'}}"
>
 <view class="picker">
  {{fenlei_title}}
 </view>
</picker>

Page({
 data: {
  server_url: app.globalData.URL,
  fenlei_title:'分类',
  job_cat_list:[],
  multiIndex: [0,0,0],
  filter:{
   keywords:'',
   job_cat_id:''
  }
 },
 onLoad: function () {
  this.jobcat();
 },
 jobcat: function() {
  var that = this;
  wx.request({
   url: app.globalData.URL + "/xxx/eeee",
   data: {
    x: '',
    y: ''
   },
   header: {
    'content-type': 'application/json' // 默认值
   },
   success: function (res) {
    var data = res.data.data;
    that.setData({
     job_cat_list: [data, data[0]['children'], data[0]['children'][0]['children']]
    });
   }
  });
 },
 bindjobcatchange: function(e){
  this.setData({multiIndex:e.detail.value})
 },
 bingjobcatcolumnchange: function(e){
  var index = this.data.multiIndex;
  const data = {
   job_cat_list: this.data.job_cat_list,
   multiIndex: this.data.multiIndex
  }
  this.data.multiIndex[e.detail.column] = e.detail.value;
  if (e.detail.column==0){
    data.job_cat_list[1] = this.data.job_cat_list[0][index[0]]['children'];
    data.job_cat_list[2] = data.job_cat_list[1][index[1]]['children'];
  }else if(e.detail.column===1){
    data.job_cat_list[2] = data.job_cat_list[1][index[1]]['children'];
    this.data.filter.job_cat_id = data.job_cat_list[2][index[2]]['cat_name'];
  }else if(e.detail.column===2){
   this.data.filter.job_cat_id=data.job_cat_list[2][e.detail.value]['cat_name'];
  }
  this.setData(data)
 }
})

public function jobcate(){
    $zp_job_catModel = new ZpJobCat();
    $job_cat = $zp_job_catModel->getcateAll();
    $i=0;
    $return_data = [];
    foreach ($job_cat as $key=>$val){
      $return_data[$i] = $val;
      $return_data[$i]['children'] = [];
      if (!empty($val['children'])){
        $c=0;
        foreach ($val['children'] as $k=>$v){
          $return_data[$i]['children'][$c] = $v;
          if (!empty($v['children'])){
            $return_data[$i]['children'][$c]['children'] = [];
            $m=0;
            foreach ($v['children'] as $val2){
              $return_data[$i]['children'][$c]['children'][$m] = $val2;
              $m++;
            }
          }
          $c++;
        }
      }
      $i++;
    }
    $this->_success($return_data);
}