diff --git a/inc/helpers/aksrt-avatar.php b/inc/helpers/aksrt-avatar.php
index 3da78046..8bc4a277 100644
--- a/inc/helpers/aksrt-avatar.php
+++ b/inc/helpers/aksrt-avatar.php
@@ -140,13 +140,26 @@ add_filter('get_avatar_data', static function (array $args, $subject): array {
 
 add_action('show_user_profile', 'aksrt_render_admin_avatar_field');
 add_action('edit_user_profile', 'aksrt_render_admin_avatar_field');
+add_action('user_edit_form_tag', static function (): void {
+	echo ' enctype="multipart/form-data"';
+});
+
+if (!function_exists('aksrt_is_avatar_upload_enabled')) {
+	/**
+	 * Whether local avatar uploads are enabled by attachment policy.
+	 */
+	function aksrt_is_avatar_upload_enabled(): bool {
+		$settings = class_exists('\\AKSRT\\Settings\\Settings') ? \AKSRT\Settings\Settings::get_all() : [];
+		return !isset($settings['allow_avatar_upload']) || !empty($settings['allow_avatar_upload']);
+	}
+}
 
 if (!function_exists('aksrt_render_admin_avatar_field')) {
 	/**
 	 * Render local avatar controls on the native WordPress user profile screen.
 	 */
 	function aksrt_render_admin_avatar_field(WP_User $user): void {
-		if (!current_user_can('edit_user', $user->ID)) {
+		if (!current_user_can('edit_user', $user->ID) || !aksrt_is_avatar_upload_enabled()) {
 			return;
 		}
 		?>
@@ -169,6 +182,33 @@ if (!function_exists('aksrt_render_admin_avatar_field')) {
 	}
 }
 
+add_filter('user_profile_update_errors', static function (WP_Error $errors, bool $update, WP_User $user): void {
+	if (empty($_FILES['aksrt_avatar_file']['name']) || !aksrt_is_avatar_upload_enabled()) {
+		return;
+	}
+
+	$file = $_FILES['aksrt_avatar_file'];
+	$settings = class_exists('\\AKSRT\\Settings\\Settings') ? \AKSRT\Settings\Settings::get_all() : [];
+	$max_size_mb = max(1, min(10, (int) ($settings['avatar_max_size'] ?? 2)));
+	$actual_size = !empty($file['tmp_name']) && is_readable($file['tmp_name']) ? (int) filesize($file['tmp_name']) : 0;
+	if ((int) ($file['error'] ?? UPLOAD_ERR_NO_FILE) !== UPLOAD_ERR_OK || $actual_size <= 0 || $actual_size > $max_size_mb * MB_IN_BYTES) {
+		$errors->add('aksrt_avatar_size', sprintf(__('头像文件无效或超过 %dMB', 'aksrt'), $max_size_mb));
+		return;
+	}
+
+	require_once ABSPATH . 'wp-admin/includes/file.php';
+	$checked = wp_check_filetype_and_ext($file['tmp_name'], $file['name'], [
+		'jpg|jpeg|jpe' => 'image/jpeg',
+		'png'          => 'image/png',
+		'gif'          => 'image/gif',
+		'webp'         => 'image/webp',
+	]);
+	$image_size = wp_getimagesize($file['tmp_name']);
+	if (empty($checked['type']) || empty($checked['ext']) || !wp_match_mime_types('image', $checked['type']) || !$image_size || ((int) $image_size[0] * (int) $image_size[1]) > 40000000) {
+		$errors->add('aksrt_avatar_type', __('头像必须是有效的 JPG、PNG、GIF 或 WebP 图片，且总像素不能超过 4000 万。', 'aksrt'));
+	}
+}, 10, 3);
+
 add_action('personal_options_update', 'aksrt_save_admin_avatar_field');
 add_action('edit_user_profile_update', 'aksrt_save_admin_avatar_field');
 
@@ -177,7 +217,7 @@ if (!function_exists('aksrt_save_admin_avatar_field')) {
 	 * Save local avatar changes from the native WordPress profile screen.
 	 */
 	function aksrt_save_admin_avatar_field(int $user_id): void {
-		if (!current_user_can('edit_user', $user_id)) {
+		if (!current_user_can('edit_user', $user_id) || !aksrt_is_avatar_upload_enabled()) {
 			return;
 		}
 		$nonce = isset($_POST['aksrt_admin_avatar_nonce']) ? sanitize_text_field(wp_unslash($_POST['aksrt_admin_avatar_nonce'])) : '';
@@ -200,11 +240,23 @@ if (!function_exists('aksrt_save_admin_avatar_field')) {
 		$settings = class_exists('\\AKSRT\\Settings\\Settings') ? \AKSRT\Settings\Settings::get_all() : [];
 		$max_size = max(1, min(10, (int) ($settings['avatar_max_size'] ?? 2))) * MB_IN_BYTES;
 		$file = $_FILES['aksrt_avatar_file'];
-		if ((int) ($file['error'] ?? UPLOAD_ERR_NO_FILE) !== UPLOAD_ERR_OK || (int) ($file['size'] ?? 0) <= 0 || (int) $file['size'] > $max_size) {
+		$actual_size = !empty($file['tmp_name']) && is_readable($file['tmp_name']) ? (int) filesize($file['tmp_name']) : 0;
+		if ((int) ($file['error'] ?? UPLOAD_ERR_NO_FILE) !== UPLOAD_ERR_OK || $actual_size <= 0 || $actual_size > $max_size) {
 			return;
 		}
 
 		require_once ABSPATH . 'wp-admin/includes/file.php';
+		$checked = wp_check_filetype_and_ext($file['tmp_name'], $file['name'], [
+			'jpg|jpeg|jpe' => 'image/jpeg',
+			'png'          => 'image/png',
+			'gif'          => 'image/gif',
+			'webp'         => 'image/webp',
+		]);
+		$image_size = wp_getimagesize($file['tmp_name']);
+		if (empty($checked['type']) || empty($checked['ext']) || !wp_match_mime_types('image', $checked['type']) || !$image_size || ((int) $image_size[0] * (int) $image_size[1]) > 40000000) {
+			return;
+		}
+
 		require_once ABSPATH . 'wp-admin/includes/media.php';
 		require_once ABSPATH . 'wp-admin/includes/image.php';
 		$attachment_id = media_handle_upload('aksrt_avatar_file', 0, [], [