开场

Ⅰ：直接引用代码来实现

<link rel="stylesheet" href="https://api.beixibaobao.com/css/bilibili-player/bofangqi.css"

<iframe src="//player.bilibili.com/player.html?aid=74725430&cid=127822972&page=1" scrolling="no" border="0" frameborder="no" framespacing="0" allowfullscreen="true"> </iframe>

<iframe class="iframe_video" src="//player.bilibili.com/player.html?aid=74725430&cid=127822972&page=1" scrolling="no" border="0" frameborder="no" framespacing="0" allowfullscreen="true"> </iframe>

Ⅱ：把代码加载自己的网站来实现

/*下方是视频挂载*/

.iframe_video {
    position: relative;
    width: 100%;
}

@media only screen and (max-width: 767px) {
 .iframe_video {
     height: 15em;
}
}

@media only screen and (min-width: 768px) and (max-width: 991px) {
    .iframe_video {
      height: 20em;
}
}

@media only screen and (min-width: 992px) and (max-width: 1199px) {
    .iframe_video {
     height: 30em;
}
}

@media only screen and (min-width: 1200px) {
    .iframe_video {
        height: 40em;
    }
}

.iframe_cross {
    position: relative;
    width: 100%;
    height: 0;
    padding-bottom: 75%
}

.iframe_cross iframe {
    position: absolute;
    width: 100%;
    height: 100%;
    left: 0;
    top: 0
}

然后我们找到b站的分享按钮得到的代码：如下：

<iframe src="//player.bilibili.com/player.html?aid=74725430&cid=127822972&page=1" scrolling="no" border="0" frameborder="no" framespacing="0" allowfullscreen="true"> </iframe>

我们将 iframe 后面加上这个：class="iframe_video"

就变成了这样：

<iframe class="iframe_video" src="//player.bilibili.com/player.html?aid=74725430&cid=127822972&page=1" scrolling="no" border="0" frameborder="no" framespacing="0" allowfullscreen="true"> </iframe>

然后就可以正常访问啦~（自动适配手机端的大小）