对我来说，这是最好的解决方案:

HTML:

<div id="outer">
    <img src="logo.png">
</div>

CSS:

#outer {
  position: fixed;
  top: 50%;
  left: 50%;
  /* Bring your own prefixes */
  transform: translate(-50%, -50%);
}

你可以在父div中使用flex属性，并将margin:auto属性添加到子条目中:

.parent {
    display: flex;
    /* You can change this to `row` if you want the items side by side instead of stacked */
    flex-direction: column;
}

/* Change the `p` tag to what your items child items are */
.parent p {
    margin: auto;
}

你可以在这里看到更多flex的选项:https://css-tricks.com/snippets/css/a-guide-to-flexbox/

这招对我很管用:

.center-stuff{
    text-align: center;
    vertical-align: middle;
    line-height: 230px; /* This should be the div height */
}

<div class="small-container">
    <span>Text centered</span>
</div>

<style>
.small-container {
    width:250px;
    height:250px;
    border:1px green solid;
    text-align:center;
    position: absolute;
    top: 50%;
    left: 50%;
    -moz-transform: translateX(-50%) translateY(-50%);
    -webkit-transform: translateX(-50%) translateY(-50%);
    transform: translateX(-50%) translateY(-50%);
}
.small-container span{
    position: absolute;
    top: 50%;
    left: 50%;
    -moz-transform: translateX(-50%) translateY(-50%);
    -webkit-transform: translateX(-50%) translateY(-50%);
    transform: translateX(-50%) translateY(-50%);
}
</style>

在父div中添加以下代码

display: grid;
place-items: center;

添加行显示:table-cell;到该div的CSS内容。

只有表格单元格支持vertical-align: middle;，但是你可以把[table-cell]定义给div…

一个活生生的例子在这里:http://jsfiddle.net/tH2cc/

div{
    height: 90px;
    width: 90px;
    text-align: center;
    border: 1px solid silver;
    display: table-cell; /* This says treat this element like a table cell */
    vertical-align:middle; /* Now we can center vertically like in a TD */
}