把下面的代码放进你所用主题的single.php文件的while主循环之内：
<nav?id="nav-single"><span?class="nav-previous"><?php?previous_post_link(?$format='<span?class="left-arrow"></span>?%link?',?$link='%title',?$in_same_cat?=?false,?$excluded_categories?=?'');?></span>
<span?class="nav-next"><?php?next_post_link($format='?%link?<span?class="right-arrow"></span>',?$link='%title',?$in_same_cat?=?false,?$excluded_categories?=?'');?></span>
</nav><!--?#nav-single?-->
CSS请参考WP自带的2013主题的style中的1714-1723行，外加：
.left-arrow:before,.right-arrow:after{width:?14px;
height:?14px;
display:?inline-block;
padding:?8px?0;
color:?#999;
font:?400?14px/1?dashicons!important;
font-weight:?normal;
font-style:?normal;
speak:?none;
text-align:?center;
vertical-align:?middle;
-webkit-font-smoothing:?antialiased;
-moz-osx-font-smoothing:?grayscale;
-moz-transition:?all?.1s?ease-in-out;
-webkit-transition:?all?.1s?ease-in-out;
transition:?all?.1s?ease-in-out;
}
.left-arrow:before{
content:?"\f340";
}
.right-arrow:after{
content:?"\f344";
} 你需要在主题前台载入WP自带的dashicons才会有左右箭头出现，如下图
测试截图：