你可以钩住add_attachment 并强制slug按如下方式处理文件名：

Update: 要使slug大写，需要在wp_unique_post_slug. 你不能简单地使用strtoupper( $slug ) WordPress在更新函数中清理（小写）。

/**
 * Force attachment slug to ignore title from metadata (if any).
 * 
 * @link http://wordpress.stackexchange.com/q/140132/1685
 * 
 * @param int $post_id
 */
function wpse_140132_attachment_slug_as_file_name( $post_id ) {
    if ( $post = get_post( $post_id ) ) {
        if ( $file = get_attached_file( $post->ID ) ) {
            // Get file name, without extension.
            $slug = pathinfo( $file, PATHINFO_FILENAME );

            // Only update if different to current slug!
            if ( $slug && $slug != $post->post_name ) {
                add_filter( \'wp_unique_post_slug\', \'wpse_140132_attachment_slug_as_file_name_uppercase\', 50 );
                wp_update_post(
                    array(
                        \'ID\' => $post->ID,
                        \'post_name\' => $slug,
                    )
                );
                remove_filter( \'wp_unique_post_slug\', \'wpse_140132_attachment_slug_as_file_name_uppercase\', 50 );
            }
        }
    }
}

add_action( \'add_attachment\', \'wpse_140132_attachment_slug_as_file_name\' );

/**
 * @see     wpse_140132_attachment_slug_as_file_name()
 * 
 * @param   string  $slug
 * @return  string
 */
function wpse_140132_attachment_slug_as_file_name_uppercase( $slug ) {
    return strtoupper( $slug );
}