在钩子函数中这样写:

mounted: function() {
  (async function(){
    console.log(1)
    var a = await that.testFunc1()
    console.log(a)
    console.log(3)
  })();
},
methods: {
  testFunc1: function() {
    return new Promise((resolve, reject)=>{
      this.testFunc2("","",res=>{
        resolve(res);
      });
    });
  },
  testFunc2: function(url,params,callback) {
    setTimeout(()=>{
      callback(2);
    },1000);
  }
}

 打印结果: