<script>
var OriginTitile = document.title,
titleTime;
document.addEventListener("visibilitychange",
function() {
    if (document.hidden) {
        $('[rel="shortcut icon"]').attr("href", "崩溃图标地址");
        document.title = "(●—●)喔哟,崩溃啦!";
        clearTimeout(titleTime)
    } else {
        $('[rel="shortcut icon"]').attr("href", "图标地址");
        document.title = "(/≧▽≦/)咦!又好了 | " + OriginTitile;
        titleTime = setTimeout(function() {
            document.title = OriginTitile
        },
        2000)
    }
});
</script>

在主题header.php(页首)文件中的前面添加就可以