SOURCE

// $("#container").on('scroll',function(){
//   console.log($("#child").offset().left)
// })
$("#container")[0].scrollTo(30,0)
console.log($("#container")[0].)

<div id="container">
  <div id="parent">
  <div id="child">子元素</div>
</div>
</div>

*{
  margin:0;
  padding:0;
}
#container{
  width:100px;
  overflow-x:auto;
  margin-left:100px;
}
#parent{
  width: 300px;
  height: 100px;
  border:1px solid black;
  border-radius:5px;
  #child{
    width: 50px;
    height: 50px;
    border:1px solid green;
    border-radius:4px;
    line-height:50px;
    float:right;
  }
}