解决办法:
body{
width: 100%;
background-image:url('url);
background-repeat: no-repeat;
background-position: center;
background-attachment: fixed;
z-index: -1;
}
兼容性:
body:before {
content: ’ ';
position: fixed;
z-index: -1;
top: 0;
right: 0;
bottom: 0;
left: 0;
background: url('url) center 0 no-repeat;
background-size: cover;
}