宽高比为5:1的比例 box { padding:10% 50%; position:relative; } .box > img { position:absolute; width:100%; height:100%; left:0; top:0; } <div class="container"> <div class="box"> <img src="https://calbum.qiniu.songxingguo.com/album/0/201912081728_%E4%B8%8A%E6%B5%B7-%E9%BB%84%E6%B5%A6_7_0/tiny" alt=""> </div> </div> 演示地址 保持宽高比 padding-top <div class="container"> <img class="media" src="..." alt="..."> </div> .container { position: relative; width: 100%; padding-top: 56.25%; /* 16:9 Aspect Ratio */ } .media { position: absolute; top: 0; } 参考地址 object-fit: contain; 实现自适应显示 .img-contanier { height: 100%; width: 100%; object-fit: contain; } 扩展阅读 aspect-ratio