diff --git a/assets/admin/src/schema/sections/post-list/thumb.js b/assets/admin/src/schema/sections/post-list/thumb.js
index 3345c629..8cc16e4c 100644
--- a/assets/admin/src/schema/sections/post-list/thumb.js
+++ b/assets/admin/src/schema/sections/post-list/thumb.js
@@ -7,7 +7,6 @@ export const thumbSchema = {
     thumb_priority: 'featured,attachment,resource,custom',
     thumb_fallback: 'placeholder',
     thumb_spare_images: [],
-    thumb_lazy: true,
     thumb_aspect_ratio: '16:9',
     list_thumb_fit: 'cover',
     thumb_multi_enabled: false,
@@ -63,7 +62,6 @@ export const thumbSchema = {
         { key: 'thumb_multi_enabled', label: '多图卡片', type: 'switch', default: false, help: '当文章有多张图片时，在列表中展示多图预览' },
         { key: 'thumb_multi_count', label: '最多显示几张', type: 'number', default: 3, min: 2, max: 6, dependsOn: { key: 'thumb_multi_enabled', value: true } },
         { key: 'mult_thumb_cat', label: '按分类多图显示', type: 'taxonomy_select', taxonomy: 'category', multiple: true, default: [], help: '选择的分类下所有文章自动显示多张缩略图' },
-        { key: 'thumb_lazy', label: '懒加载', type: 'switch', default: true },
       ],
     },
   ],
diff --git a/inc/helpers/posts-renderer/config.php b/inc/helpers/posts-renderer/config.php
index 0677edfc..a0a6866b 100644
--- a/inc/helpers/posts-renderer/config.php
+++ b/inc/helpers/posts-renderer/config.php
@@ -39,7 +39,6 @@ if (!function_exists('aksrt_renderer_defaults')) {
 			'show_thumb'           => true,
 			'thumb_ratio'          => '4:3',
 			'thumb_fit'            => 'cover',
-			'thumb_lazy'           => true,
 			'thumb_if_has'         => false,
 			'target_blank'         => false,
 			'title_html'           => '',
@@ -328,9 +327,13 @@ if (!function_exists('aksrt_renderer_resolve_images')) {
 		}
 
 		$thumb_settings = class_exists('\AKSRT\Settings\Settings') ? \AKSRT\Settings\Settings::get_post_thumb_settings() : [];
-		$allow_fallback = !empty($thumb_settings['rand_thumb']) || !empty($cfg['thumb_if_has']);
-		if ($primary === '' && $allow_fallback) {
-			$primary = aksrt_renderer_random_fallback_image($post_id);
+		$fallback = sanitize_key((string) ($thumb_settings['fallback'] ?? 'placeholder'));
+		if ($primary === '' && empty($cfg['thumb_if_has'])) {
+			if ($fallback === 'random') {
+				$primary = aksrt_renderer_random_fallback_image($post_id);
+			} elseif ($fallback === 'placeholder') {
+				$primary = aksrt_get_lazy_thumb();
+			}
 		}
 
 		return [
diff --git a/inc/helpers/posts-renderer/markup.php b/inc/helpers/posts-renderer/markup.php
index 940f72ae..c777ad22 100644
--- a/inc/helpers/posts-renderer/markup.php
+++ b/inc/helpers/posts-renderer/markup.php
@@ -170,9 +170,7 @@ if (!function_exists('aksrt_renderer_mini')) {
 		$target_attr = !empty($cfg['target_blank']) ? ' target="_blank"' : '';
 		if ($cfg['show_thumb'] && !empty($data['has_img'])) {
 			$fit_class = !empty($cfg['thumb_fit']) && $cfg['thumb_fit'] === 'contain' ? 'fit-contain' : 'fit-cover';
-			$thumb_attr = !empty($cfg['thumb_lazy'])
-				? aksrt_get_lazy_attr('lazy_posts_thumb', (string) $data['img_url'], $fit_class)
-				: ' class="' . esc_attr($fit_class) . '" src="' . esc_url($data['img_url']) . '"';
+			$thumb_attr = aksrt_get_lazy_attr('lazy_posts_thumb', (string) $data['img_url'], $fit_class);
 			$thumb_img = '<img' . $thumb_attr . ' alt="' . esc_attr($data['title']) . '">';
 
 			$thumb_html = '<a href="' . esc_url($data['permalink']) . '" class="item-thumbnail" aria-label="' . esc_attr($data['title']) . '"' . $target_attr . '>' . $thumb_img . '</a>';
diff --git a/inc/helpers/posts-renderer/post-data.php b/inc/helpers/posts-renderer/post-data.php
index 60535c00..8bbecd71 100644
--- a/inc/helpers/posts-renderer/post-data.php
+++ b/inc/helpers/posts-renderer/post-data.php
@@ -113,9 +113,7 @@ if (!function_exists('aksrt_renderer_thumb')) {
 		$has_real_img = !empty($data['has_real_img']);
 
 		$fit_class = !empty($cfg['thumb_fit']) && $cfg['thumb_fit'] === 'contain' ? 'fit-contain' : 'fit-cover';
-		$img_attr = !empty($cfg['thumb_lazy'])
-			? aksrt_get_lazy_attr('lazy_posts_thumb', $img, $fit_class)
-			: ' class="' . esc_attr($fit_class) . '" src="' . esc_url($img) . '"';
+		$img_attr = aksrt_get_lazy_attr('lazy_posts_thumb', $img, $fit_class);
 		$img_html = '<img' . $img_attr . ' alt="' . esc_attr($title) . '">';
 
 		$sticky_html = ($is_sticky && !empty($cfg['badge_show']))
diff --git a/src/Admin/Schema/SchemaPostList.php b/src/Admin/Schema/SchemaPostList.php
index 0134fe28..9a95f299 100644
--- a/src/Admin/Schema/SchemaPostList.php
+++ b/src/Admin/Schema/SchemaPostList.php
@@ -55,7 +55,6 @@ class SchemaPostList {
                             ['key' => 'thumb_multi_enabled', 'label' => '多图卡片', 'type' => 'switch', 'default' => false],
                             ['key' => 'thumb_multi_count', 'label' => '最多显示几张', 'type' => 'number', 'default' => 3, 'min' => 2, 'max' => 6, 'dependsOn' => ['key' => 'thumb_multi_enabled', 'value' => true]],
                             ['key' => 'mult_thumb_cat', 'label' => '按分类多图显示', 'type' => 'taxonomy_select', 'taxonomy' => 'category', 'multiple' => true, 'default' => [], 'dependsOn' => ['key' => 'thumb_multi_enabled', 'value' => true]],
-                            ['key' => 'thumb_lazy', 'label' => '懒加载', 'type' => 'switch', 'default' => true, 'dependsOn' => ['key' => 'thumb_multi_enabled', 'value' => true]],
                         ]],
                     ],
                 ],
diff --git a/src/Settings/DisplayPageGroups.php b/src/Settings/DisplayPageGroups.php
index 2b03a020..062f914c 100644
--- a/src/Settings/DisplayPageGroups.php
+++ b/src/Settings/DisplayPageGroups.php
@@ -209,7 +209,6 @@ trait DisplayPageGroups {
                 'thumb_priority'           => implode(',', $thumb['priority']),
                 'thumb_fallback'           => $thumb['fallback'],
                 'thumb_spare_images'       => $thumb['spare_images'],
-                'thumb_lazy'               => $thumb['lazy'],
                 'thumb_aspect_ratio'       => $thumb['aspect_ratio'],
                 'thumb_multi_enabled'      => $thumb['multi_enabled'],
                 'thumb_multi_count'        => $thumb['multi_count'],
diff --git a/src/Settings/PostDisplay.php b/src/Settings/PostDisplay.php
index 6c285c36..fdb1a3d0 100644
--- a/src/Settings/PostDisplay.php
+++ b/src/Settings/PostDisplay.php
@@ -174,7 +174,6 @@ class PostDisplay {
             'aspect_ratio'     => $aspect_ratio,
             'multi_enabled'    => !empty($settings['thumb_multi_enabled']),
             'multi_count'      => max(2, min(6, (int) ($settings['thumb_multi_count'] ?? 3))),
-            'lazy'             => !isset($settings['thumb_lazy']) || !empty($settings['thumb_lazy']),
             'fit'              => in_array(sanitize_key((string) ($settings['list_thumb_fit'] ?? 'cover')), ['cover', 'contain'], true) ? sanitize_key((string) ($settings['list_thumb_fit'] ?? 'cover')) : 'cover',
             'slides_s'         => !isset($settings['list_thumb_slides_s']) || !empty($settings['list_thumb_slides_s']),
             'video_s'          => !isset($settings['list_thumb_video_s']) || !empty($settings['list_thumb_video_s']),
diff --git a/tests/widget-system/lazyload-contract.test.cjs b/tests/widget-system/lazyload-contract.test.cjs
index 98e61788..72e7125a 100644
--- a/tests/widget-system/lazyload-contract.test.cjs
+++ b/tests/widget-system/lazyload-contract.test.cjs
@@ -119,6 +119,23 @@ test('one lazySizes runtime owns dynamic media, backgrounds, videos, and IAS', (
   assert.doesNotMatch(widgets, /IntersectionObserver/);
 });
 
+test('post lists have no second lazy switch and keep Zibll fallback thumbnails', () => {
+  const config = read('inc/helpers/posts-renderer/config.php');
+  const postData = read('inc/helpers/posts-renderer/post-data.php');
+  const markup = read('inc/helpers/posts-renderer/markup.php');
+  const phpSchema = read('src/Admin/Schema/SchemaPostList.php');
+  const vueSchema = read('assets/admin/src/schema/sections/post-list/thumb.js');
+  const legacyKey = 'thumb_' + 'lazy';
+
+  for (const source of [config, postData, markup, phpSchema, vueSchema]) {
+    assert.equal(source.includes(legacyKey), false);
+  }
+  assert.match(postData, /aksrt_get_lazy_attr\('lazy_posts_thumb', \$img, \$fit_class\)/);
+  assert.match(markup, /aksrt_get_lazy_attr\('lazy_posts_thumb', \(string\) \$data\['img_url'\], \$fit_class\)/);
+  assert.match(config, /\$fallback\s*=\s*sanitize_key[\s\S]*?\$fallback\s*===\s*'placeholder'[\s\S]*?aksrt_get_lazy_thumb\(\)/);
+  assert.doesNotMatch(config, /rand_thumb/);
+});
+
 test('legacy lazy identifiers and theme-native loading attributes are gone', () => {
   const files = sourceFiles(root).filter((file) => !file.endsWith('lazyload-contract.test.cjs'));
   const source = files.map((file) => fs.readFileSync(file, 'utf8')).join('\n');
@@ -128,6 +145,7 @@ test('legacy lazy identifiers and theme-native loading attributes are gone', ()
     'get_' + 'lazyload_config',
     'aksrt_' + 'lazy_img_attrs',
     'aksrt_' + 'lazy_loading',
+    'thumb_' + 'lazy',
   ];
   for (const token of forbidden) assert.equal(source.includes(token), false, token);
   assert.doesNotMatch(source, /aksrt-lazy(?!sizes)/);