嗯，我不知道这是否很好，但正在返回预期的结果。。。所以现在这对我来说已经足够了。

function my_custom_get_terms( $my_tax, $my_category, $show_all = true ){
    global $wpdb;
    global $pagename;

    $query = "SELECT Count(wp_posts.ID) AS my_term_count, wp_term_taxonomy.term_taxonomy_id, wp_term_taxonomy.taxonomy, wp_terms.name, wp_terms.term_id, wp_terms.slug AS term_slug, wp_terms.term_group, wp_terms_1.slug
    FROM (((((wp_term_relationships INNER JOIN wp_term_taxonomy ON wp_term_relationships.term_taxonomy_id = wp_term_taxonomy.term_taxonomy_id) INNER JOIN wp_terms ON wp_term_taxonomy.term_id = wp_terms.term_id) INNER JOIN wp_posts ON wp_term_relationships.object_id = wp_posts.ID) INNER JOIN wp_term_relationships AS wp_term_relationships_1 ON wp_posts.ID = wp_term_relationships_1.object_id) INNER JOIN wp_term_taxonomy AS wp_term_taxonomy_1 ON wp_term_relationships_1.term_taxonomy_id = wp_term_taxonomy_1.term_taxonomy_id) INNER JOIN wp_terms AS wp_terms_1 ON wp_term_taxonomy_1.term_id = wp_terms_1.term_id
    GROUP BY wp_term_taxonomy.term_taxonomy_id, wp_term_taxonomy.taxonomy, wp_terms.name, wp_terms.term_id, wp_terms.slug, wp_terms.term_group, wp_terms_1.slug
    HAVING (((wp_term_taxonomy.taxonomy)=\'$my_tax\') AND ((wp_terms_1.slug) = \'$my_category\'))
    ORDER BY Count(wp_posts.ID) DESC";

    $datos = $wpdb->get_results($query, OBJECT);
    echo "<ul>";
    $total = 0;
    foreach ( $datos as $dato ) {
        echo \'<li><a href="\' . get_bloginfo(\'url\') . \'/\' . get_parent_page_slug() . \'/\' . $pagename . \'/?tipo=\' . $dato->term_slug . \'">\' . $dato->name . \' (\' . $dato->my_term_count . \')</a></li>\';
        $total += $dato->my_term_count;
    }

    if ( $show_all ){
        echo \'<li><a href="\' . get_bloginfo(\'url\') . \'/\' . get_parent_page_slug() . \'/\' . $pagename . \'/">Todos (\' . $total . \')</a></li>\';
    }
    echo "</ul>";
}



my_custom_get_terms( \'tipo\', get_parent_page_slug(), true );