添加这种重写规则不是问题，您只需添加此代码。

/**
 * Add custom rewrite rule to handle posts with and without category prefix.
 *
 * Remember to flush rewrite rules to apply changes.
 */
function wpse_288675_add_post_handling_without_category_prefix() {

    add_rewrite_rule(\'([^/]+)(?:/([0-9]+))?/?$\', \'index.php?name=$matches[1]&page=$matches[2]\', \'top\');
}

问题是您的内容将通过两个链接提供。具有%category% 前缀和不带。防止duplicate content 这对SEO不利，我们必须使用301代码全部重定向not uncaterogized post to url with category 以及所有uncaterogized post to url without category. 我们可以使用下面的代码来实现这一点。

/**
 * Check if displayed post have category and which category to maybe redirect user
 * with 301 code to prevent duplicate content.
 */
function wpse_288675_maybe_redirect( $query ) {

    // Define uncaterogized category id for convenience
    if( ! defined( \'UNCATEROGIZED_CATEGORY_ID\' ) ) {
        define( \'UNCATEROGIZED_CATEGORY_ID\', 1 );
    }

    // Do not parse request on some conditions
    if( !is_admin() && $query->is_main_query() && $query->is_single() ) { 

        // Get post name and category from url
        $slug          = $query->get(\'name\');
        $category_name = $query->get(\'category_name\');

        $query = new WP_Query(array(
            \'post_type\' => \'post\',
            \'name\' => $slug,
        ));

        if( $query->have_posts() ) {

            // Get current post
            $posts = $query->get_posts();
            $post = current($posts);

            // Get post current first category
            $categories = get_the_category( $post->ID );
            $category   = current($categories);

            // If there is no category in url redirect
            // all not uncaterogized post to url with category
            if( !$category_name && $category->term_id !== UNCATEROGIZED_CATEGORY_ID ) { 
                wp_safe_redirect( get_permalink( $post->ID ), 301 );
                exit;
            }

            // If there is category in url redirect
            // all uncaterogized post to url without category
            if($category_name && $category->term_id === UNCATEROGIZED_CATEGORY_ID ) { 

                $url_format = \'%s/%s/\';
                $url = sprintf($url_format, get_bloginfo(\'url\'), $slug);

                wp_safe_redirect( $url, 301 );
                exit;
            }
        }
    }

    return $query;
}

add_filter( \'pre_get_posts\', \'wpse_288675_maybe_redirect\' );

• Test 1 带类别Uncaterogized
• Test 2 带类别Category 1/uncaterogized/test-1/ 我正在重定向到/test-1/.当我到达/category-1/test-2 我没有被重定向。