1. 使用css3中的属性：transform: translate(x,y)
<style> .box { width: 100px; height: 100px; background: orange; position: absolute; left: 50%; top: 50%; transform: translate(-50%, -50%); } </style> </head> <body> <div class="box"></div> </body>
2.使用flex布局
<style>
body {
display: flex;
justify-content: center;
align-items: center;
height: 100vh;
margin: 0;
padding: 0;
}
.box {
width: 100px;
height: 100px;
background: orange;
}
</style>
</head>
<body>
<div class="box"></div>
</body>
3. 使用绝对定位，加上margin-left: -(width为盒子的一半), margin-top: -(height为盒子的一半)
<style> .box { width: 100px; height: 100px; background: orange; position: absolute; left: 50%; top: 50%; margin-left: -50px; margin-top: -50px; } </style> </head> <body> <div class="box"></div> </body>