<style>
#box{
width:2000px;
height:328px;
overflow: hidden;
}
#box >div{
width: 250px;
height:328px;
background-image: url('https://img0.baidu.com/it/u=1032314795,3433105171&fm=253&fmt=auto&app=138&f=JPEG?w=889&h=500');
float: left;
cursor: pointer;
transition: width 1s;
}
#box>div:hover{
width:889px;
}
</style>
<div id="box">
<div></div>
<div></div>
<div></div>
<div></div>
</div>