SOURCE

<div class="banner">
    <div class="drop- shadow">
         <div class="glass"></div>
         <span>毛玻璃效果GLASS</ span>
    </div>
</div> 

.banner{
    width: 100Vw;
    height: 100vh;
    background: url(https://img1.baidu.com/it/u=1556755759,1061603115&fm=253&fmt=auto&app=138&f=JPEG?w=500&h=313);
    background-position: center;
    background-size: cover;
    display: flex;
    justify-content: center;
    align-items: center;
}
.glass{
    width: 100%;
    height: 100%;
    background: url(https://img1.baidu.com/it/u=1556755759,1061603115&fm=253&fmt=auto&app=138&f=JPEG?w=500&h=313);
    background-size: cover;
    background-position:center; 
    clip-path: inset(400px 400px); /*裁切*/
    filter: blur(20px); /*滤镜*/
    display: flex;
    justify-content: center;
    align-items: center;
}
.drop- shadow{
    height: 100%;
    width: 100%;
    filter: drop- shadow( 0px 20px 10px rgba(0, 0, 0, 0.5));
    display: flex;
    justify-content: center;
    align-items: center;
}