diff --git a/js/script.js b/js/script.js
index 1ce3c82..845e75b 100644
--- a/js/script.js
+++ b/js/script.js
@@ -2065,39 +2065,54 @@
         return /MicroMessenger/i.test(navigator.userAgent);
     }
 
-    // 生成画布（高清无损，根据设备像素比自适应分辨率）
+    // 生成画布（高清无损，保持与显示容器相同的宽高比）
     async function generateCanvas() {
         const canvas = exportCanvas;
         const ctx = canvas.getContext('2d');
         const container = imageContainer;
 
-        // 根据设备像素比决定输出分辨率，移动端至少 2x
-        // 微信等浏览器 canvas 最大尺寸通常为 4096，所以上限设为 2160×3840
-        const dpr = window.devicePixelRatio || 1;
-        const minScale = Math.max(dpr, 2); // 至少 2x
+        // 获取显示容器的实际尺寸和宽高比
         const displayWidth = container.clientWidth;
         const displayHeight = container.clientHeight;
+        const displayRatio = displayWidth / displayHeight;
         
+        // 根据设备像素比决定输出分辨率，移动端至少 2x
+        const dpr = window.devicePixelRatio || 1;
+        const minScale = Math.max(dpr, 2); // 至少 2x
+        
+        // 先计算目标尺寸
         let TARGET_WIDTH = Math.round(displayWidth * minScale);
         let TARGET_HEIGHT = Math.round(displayHeight * minScale);
         
         // 微信特殊处理：微信内置浏览器 canvas 限制更严格
-        // 实测微信中 4096 可能不稳定，使用 2048 更安全
         const MAX_CANVAS_SIZE = isWechat() ? 2048 : 4096;
-        if (TARGET_HEIGHT > MAX_CANVAS_SIZE) {
-            const ratio = MAX_CANVAS_SIZE / TARGET_HEIGHT;
-            TARGET_WIDTH = Math.round(TARGET_WIDTH * ratio);
-            TARGET_HEIGHT = MAX_CANVAS_SIZE;
-        }
-        if (TARGET_WIDTH > MAX_CANVAS_SIZE) {
-            const ratio = MAX_CANVAS_SIZE / TARGET_WIDTH;
-            TARGET_HEIGHT = Math.round(TARGET_HEIGHT * ratio);
-            TARGET_WIDTH = MAX_CANVAS_SIZE;
+        
+        // 如果超出限制，按宽高比等比例缩放
+        if (TARGET_HEIGHT > MAX_CANVAS_SIZE || TARGET_WIDTH > MAX_CANVAS_SIZE) {
+            const maxDimension = Math.max(TARGET_WIDTH, TARGET_HEIGHT);
+            const scaleFactor = MAX_CANVAS_SIZE / maxDimension;
+            TARGET_WIDTH = Math.round(TARGET_WIDTH * scaleFactor);
+            TARGET_HEIGHT = Math.round(TARGET_HEIGHT * scaleFactor);
         }
         
-        // 确保最小分辨率
-        TARGET_WIDTH = Math.max(TARGET_WIDTH, 1080);
-        TARGET_HEIGHT = Math.max(TARGET_HEIGHT, 1920);
+        // 确保最小分辨率，同时保持宽高比
+        const minWidth = 1080;
+        const minHeight = 1920;
+        if (TARGET_WIDTH < minWidth || TARGET_HEIGHT < minHeight) {
+            const widthScale = minWidth / TARGET_WIDTH;
+            const heightScale = minHeight / TARGET_HEIGHT;
+            const scaleFactor = Math.max(widthScale, heightScale);
+            TARGET_WIDTH = Math.round(TARGET_WIDTH * scaleFactor);
+            TARGET_HEIGHT = Math.round(TARGET_HEIGHT * scaleFactor);
+            
+            // 再次检查是否超出限制
+            if (TARGET_HEIGHT > MAX_CANVAS_SIZE || TARGET_WIDTH > MAX_CANVAS_SIZE) {
+                const maxDimension = Math.max(TARGET_WIDTH, TARGET_HEIGHT);
+                const limitScale = MAX_CANVAS_SIZE / maxDimension;
+                TARGET_WIDTH = Math.round(TARGET_WIDTH * limitScale);
+                TARGET_HEIGHT = Math.round(TARGET_HEIGHT * limitScale);
+            }
+        }
         
         console.log('目标画布尺寸:', TARGET_WIDTH, 'x', TARGET_HEIGHT, 'dpr:', dpr, '微信:', isWechat());
         console.log('显示容器尺寸:', displayWidth, 'x', displayHeight);