<picker 
 mode="multiSelector" 
 bindchange="bindCustomPickerChange" 
 bindcolumnchange="bindCustomPickerColumnChange" 
 value="{{customIndex}}" 
 range="{{onlyArray}}"
 >
 <view>
  多列自创选择器：{{onlyArray[0][customIndex[0]]}}，{{onlyArray[1][customIndex[1]]}}，{{onlyArray[2][customIndex[2]]}}
 </view>
</picker>

Page({

 /**
 * 页面的初始数据
 */
 data: {
 //当前选中数组的下标值
 customIndex: [0, 0, 0],
 //当前选中数组
 onlyArray: [
  [],
  [],
  []
 ],
 //customArray假设为我们从后台获取到的json数据
 customArray: [{
  name: '百度',
  dept: [{
   name: '搜索',
   product: [{
    name: '百度搜索'
    },
    {
    name: '百度一下'
    },
   ]
   },
   {
   name: '团购',
   product: [{
    name: '百度糯米'
   }, {
    name: '饿了么'
   }]
   },
   {
   name: '音乐',
   product: [{
    name: '百度音乐'
   }]
   },
   {
   name: '问答社区',
   product: [{
    name: '百度贴吧'
   }]
   }
  ]
  },

  {
  name: '腾讯',
  dept: [{
   name: '社交',
   product: [{
    name: 'QQ'
    },
    {
    name: '微信'
    },
   ]
   },
   {
   name: '视频',
   product: [{
    name: '腾讯视频'
    },
    {
    name: '搜狐视频'
    },
   ]
   },

   {
   name: '短视频',
   product: [{
    name: '微视'
   }]
   }
  ]
  },
 ],
 },

 /**
 * 生命周期函数--监听页面加载
 */
 onLoad: function(options) {
 var data = {
  customArray: this.data.customArray,
  customIndex: this.data.customIndex,
  onlyArray: this.data.onlyArray,
 };
 for (var i = 0; i < data.customArray.length; i++) {
  data.onlyArray[0].push(data.customArray[i].name);
 }
 for (var j = 0; j < data.customArray[data.customIndex[0]].dept.length; j++) {
  data.onlyArray[1].push(data.customArray[data.customIndex[0]].dept[j].name);
 }
 for (var k = 0; k < data.customArray[data.customIndex[0]].dept[data.customIndex[1]].product.length; k++) {
  data.onlyArray[2].push(data.customArray[data.customIndex[0]].dept[data.customIndex[1]].product[k].name);
 }
 this.setData(data);
 },

//多列自定义选择器改变value的方法
 bindCustomPickerChange: function(e) {
 var customArray = this.data.customArray,
  customIndex = this.data.customIndex,
  onlyArray = this.data.onlyArray;

 console.log('picker发送选择改变，携带值为', e.detail.value);
 //此处e.detail.value为当前选择的列的下标值数组，如[0,1,0]
 
 console.log('picker最终选择值为：', onlyArray[0][customIndex[0]], onlyArray[1][customIndex[1]], onlyArray[2][customIndex[2]]);
 this.setData({
  customIndex: e.detail.value
 })
 },

 //多列自创选择器换列方法
 bindCustomPickerColumnChange: function(e) {
 var customArray = this.data.customArray,
  customIndex = this.data.customIndex,
  onlyArray = this.data.onlyArray;

 customIndex[e.detail.column] = e.detail.value;
 // console.log(onlyArray);

 var searchColumn = () => {
  for (var i = 0; i < customArray.length; i++) {
  var arr1 = [];
  var arr2 = [];
  if (i == customIndex[0]) {
   for (var j = 0; j < customArray[i].dept.length; j++) {
   arr1.push(customArray[i].dept[j].name);
   if (j == customIndex[1]) {
    for (var k = 0; k < customArray[i].dept[j].product.length; k++) {
    arr2.push(customArray[i].dept[j].product[k].name);
    }
    onlyArray[2] = arr2;
   }
   }
   onlyArray[1] = arr1;
  }
  };
 }

 switch (e.detail.column) {
  case 0:
  customIndex[1] = 0;
  customIndex[2] = 0;
  searchColumn();
  break;
  case 1:
  customIndex[2] = 0;
  searchColumn();
  break;
 }
 this.setData({
  onlyArray: onlyArray,
  customIndex: customIndex
 });
 },