code：
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title></title>
<style>
* {
margin: 0;
padding: 0;
}
div {
width: 567px;
height: 567px;
margin: auto;
background: url(https://timgsa.baidu.com/timg?image&quality=80&size=b9999_10000&sec=1541567263299&di=fd0a7bdfe446f9656c3036f7c4833489&imgtype=0&src=http%3A%2F%2Fs2.sinaimg.cn%2Fmiddle%2F005Jkwzugy6LsIDL9rrc1%26690) no-repeat;
transform: rotate(0deg);
transition:transform 2s ease-in-out 1s;
}
div:hover{
transform: rotate(180deg);
}
</style>
</head>
<body>
<div></div>
</body>
</html>