diff --git a/plugins/message_summary/main.py b/plugins/message_summary/main.py
index 1c7cad1..df7b485 100644
--- a/plugins/message_summary/main.py
+++ b/plugins/message_summary/main.py
@@ -110,6 +110,13 @@ class MessageSummaryPlugin(MessagePluginInterface):
             self._summary_image_template_path = str(
                 output_config.get("summary_image_template_path", "plugins/message_summary/templates/summary_card.html")
             ).strip()
+            # 模板截图视口参数：
+            # 1. 支持在插件配置中单独传入宽度/高度/缩放；
+            # 2. 默认保持历史值（780/960/1.2），避免影响未配置场景；
+            # 3. 仅在 template 模式生图时使用，markdown 模式不受影响。
+            self._template_viewport_width = int(output_config.get("template_viewport_width", 780))
+            self._template_viewport_height = int(output_config.get("template_viewport_height", 960))
+            self._template_device_scale_factor = float(output_config.get("template_device_scale_factor", 1.2))
             self.llm_client = UnifiedLLMClient(api_config)
             self._api_mode = self.llm_client.mode or self._api_mode
             self._response_mode = self.llm_client.response_mode or self._response_mode
@@ -1489,7 +1496,16 @@ class MessageSummaryPlugin(MessagePluginInterface):
                     message_stats=message_stats,
                     metadata=metadata,
                 )
-                await asyncio.wait_for(html_to_image(html_content, str(output_path)), timeout=total_timeout)
+                await asyncio.wait_for(
+                    html_to_image(
+                        html_content,
+                        str(output_path),
+                        viewport_width=self._template_viewport_width,
+                        viewport_height=self._template_viewport_height,
+                        device_scale_factor=self._template_device_scale_factor,
+                    ),
+                    timeout=total_timeout,
+                )
                 if not output_path.exists() or output_path.stat().st_size < 1024:
                     raise RuntimeError("模板截图输出文件异常")
                 return str(output_path.resolve())
diff --git a/utils/markdown_to_image.py b/utils/markdown_to_image.py
index 8fd377a..9185109 100644
--- a/utils/markdown_to_image.py
+++ b/utils/markdown_to_image.py
@@ -633,14 +633,35 @@ class _PersistentBrowser:
             return
         self._heartbeat_task = asyncio.create_task(self._heartbeat_loop(), name="md2img:heartbeat")
 
-    async def screenshot(self, html_content: str, output_image: str):
+    async def screenshot(
+        self,
+        html_content: str,
+        output_image: str,
+        viewport_width: int = 780,
+        viewport_height: int = 960,
+        device_scale_factor: float = 1.2,
+    ):
         browser = await self.ensure_browser()
 
         async def _capture_with_browser(active_browser):
             self._capture_in_progress = True
             context = None
             try:
-                context = await active_browser.new_context(viewport={"width": 780, "height": 960}, device_scale_factor=1.2)
+                # 说明：
+                # 1. 允许调用方按业务场景传入截图宽度（例如卡片模板可用更窄视口）；
+                # 2. 默认值保持历史行为，确保未改造调用方不受影响；
+                # 3. 这里做最小边界保护，避免传入异常值导致 Playwright 抛错。
+                safe_width = max(320, int(viewport_width or 780))
+                safe_height = max(320, int(viewport_height or 960))
+                safe_scale = float(device_scale_factor or 1.2)
+                if safe_scale < 1.0:
+                    safe_scale = 1.0
+                if safe_scale > 3.0:
+                    safe_scale = 3.0
+                context = await active_browser.new_context(
+                    viewport={"width": safe_width, "height": safe_height},
+                    device_scale_factor=safe_scale,
+                )
                 page = await context.new_page()
                 logger.debug("Set page content")
                 await page.set_content(html_content, wait_until='domcontentloaded', timeout=15000)
@@ -893,7 +914,13 @@ def warmup_md2img_browser_sync(timeout_seconds: int = 45) -> bool:
         return False
 
 
-async def html_to_image(html_content, output_image):
+async def html_to_image(
+    html_content,
+    output_image,
+    viewport_width: int = 780,
+    viewport_height: int = 960,
+    device_scale_factor: float = 1.2,
+):
     """将 HTML 渲染为图片。
 
     说明：
@@ -903,7 +930,13 @@ async def html_to_image(html_content, output_image):
 
     async def _html_to_image_impl():
         manager = _get_browser_manager()
-        await manager.screenshot(html_content, output_image)
+        await manager.screenshot(
+            html_content,
+            output_image,
+            viewport_width=viewport_width,
+            viewport_height=viewport_height,
+            device_scale_factor=device_scale_factor,
+        )
 
     await _run_in_md2img_runtime(_html_to_image_impl())