diff --git a/internal/controller/post_controller.go b/internal/controller/post_controller.go
index 8a8eb68..49c39e8 100644
--- a/internal/controller/post_controller.go
+++ b/internal/controller/post_controller.go
@@ -5,9 +5,9 @@ import (
 	"errors"
 	"fmt"
 	"image"
-	_ "image/gif"
-	_ "image/jpeg"
-	_ "image/png"
+	"image/jpeg"
+	"image/png"
+	_ "image/gif" // 仅注册 GIF 解码器，不重编码（会丢失动画）
 	"io"
 	"net/http"
 	"os"
@@ -449,11 +449,38 @@ func (ctrl *PostController) UploadImage(c *gin.Context) {
 		}
 	}
 
-	// 原格式存储（GIF / 已有 WebP / 二分压缩仍超原文件大小）
+	// 回退存储：重新编码以剥离 EXIF/元数据（GIF 例外：重编码会丢失动画）
 	if savePath == "" {
+		dataOut := data
+
+		if isJPEGPNG || isWebP {
+			var decImg image.Image
+			var decErr error
+			if isWebP {
+				decImg, decErr = webp.Decode(bytes.NewReader(data))
+			} else {
+				decImg, _, decErr = image.Decode(bytes.NewReader(data))
+			}
+			if decErr == nil {
+				var buf bytes.Buffer
+				var encErr error
+				switch {
+				case isWebP:
+					encErr = webp.Encode(&buf, decImg, &webp.Options{Quality: 80})
+				case ext == ".png":
+					encErr = png.Encode(&buf, decImg)
+				default:
+					encErr = jpeg.Encode(&buf, decImg, &jpeg.Options{Quality: 92})
+				}
+				if encErr == nil && buf.Len() > 0 {
+					dataOut = buf.Bytes()
+				}
+			}
+		}
+
 		filename := fmt.Sprintf("%d_%d%s", uid, ts, ext)
 		savePath = filepath.Join(storageDir, filename)
-		if err := os.WriteFile(savePath, data, 0644); err != nil {
+		if err := os.WriteFile(savePath, dataOut, 0644); err != nil {
 			common.Error(c, http.StatusInternalServerError, "保存图片失败")
 			return
 		}