第一种
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title></title>
<style type="text/css">
div{height:100px;100px;text-align: center;}
img{vertical-align: middle;display: inline-block;}
span{height:100%;0;vertical-align: middle;display: inline-block;}
</style>
</head>
<body>
<div>
<img src="" alt="" />
<span></span>
</div>
</body>
</html>
第二种
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title></title>
<style>
div
{
display:flex
}
img{
margin:auto;
}
</style>
</head>
<body>
<div>
<img>
</div>
</body>
</html>