SOURCE

<div class="segmenting-line">
<hr>
<div><span>分割线</span></div>
</div>

.segmenting-line {
    position: relative;
    height: 20px;
    margin: 20px 0;
    background:#fff;
}
.segmenting-line hr {
    position: absolute;
    width: 100%;
    top: 10px;
    border: none;
    height: 1px;
    margin: 0;
    background-image: linear-gradient(to right,#fff,#eee 50%,#fff);
    background-repeat: no-repeat;
}
.segmenting-line div {
    text-align: center;
    line-height: 20px;
    position: absolute;
    width: 100%;
}

.segmenting-line div span {
    margin: auto;
    padding: 0 20px;
    display: inline-block;
    background-color: #fdfdfd;
    font-size: 16px;
    color: #aaa;
}