这应该有效-使用wp_upload_dir 获取路径，然后检查它是否存在，如果不存在，则创建它。

$upload_dir = wp_upload_dir();
if (!is_dir($upload_dir[\'path\'])) {  // directory doesn\'t exist
    mkdir($structure, 0744, true); // the mode to use here may vary based on your hosting environment
}