您可以使用JQuery autocomplete plugin

一旦包含了所有需要的JS文件，只需在新的帖子表单后添加此代码

$terms = get_terms("post_tag");
$tags = \'\';
$count = count($terms);
 if ( $count > 0 ){ 
     foreach ( $terms as $term ) {
       $tags .=  \'"\'.$term->name.\'", \'; 
    }
    $tags = substr($tags,0,-2);
 }

echo \' <script>
JQuery("#post_tags").autocomplete([\'.$tags.\'], {
        width: 320,
        max: 4,
        highlight: true,
        multiple: true,
        multipleSeparator: ", ",
        scroll: true,
        scrollHeight: 300
    });
</script>\';