get_the_tags 将返回一个标记对象，因此您必须创建一个post标记数组，然后查看$tag->name 位于post tags数组中。

$tags = get_tags();
    $post_tags = get_the_tags($post->ID);

    /* Just make an array so you can use in_array function later on */
    $post_tag_array = array();
    foreach( $post_tags as $post_tag ){
        array_push($post_tag_array,$post_tag->name);
    }

    if ($tags) {
      foreach ($tags as $tag) {
        /* Then change to search this array for the $tag->name */
        if( (is_tag($tag)) || ( in_array($tag->name, $post_tag_array )) ){ 
          echo \'<a href="\'.get_tag_link($tag->term_id).\'" title="\'.$tag->name.\'" class="currenttag">\'.$tag->name.\'</a> \'; 
          } else {
          echo \'<a href="\'.get_tag_link($tag->term_id).\'" title="\'.$tag->name.\'"">\'.$tag->name.\'</a> \';
          }
        }
      }