css.vid-wrap{ width:100%;background: #000; position:relative; padding-bottom:56.25%; /*需要用padding来维持16:9比例,也就是9除以16*/ height: 0;}.vid-wrap video{ position: absolute; top:0; left: 0; width: 100%; height: 100%}
html<div class="vid-wrap"> <video controls autoplay loop><source src="" type="video/mp4"> </video></div