//index.js
// 从从60到到0倒计时
function countdown(that) {
  var second = that.data.second
  if (second == 0) {
   that.setData({
    second: "60秒倒计时结束"
   });
   return ;
  }
  var time = setTimeout(function(){
   that.setData({
    second: second - 1
   });
   countdown(that);
  }
  ,1000)
}

Page({
   data: {
     second: 10
   },
   onLoad: function() {
     countdown(this);
   }
});

<!--index.wxml-->
<view class="container">
<text>倒计时: {{second}} </text>
</view>