diff --git a/service/src/main/java/cn/qihangerp/service/external/pdd/PddPopClient.java b/service/src/main/java/cn/qihangerp/service/external/pdd/PddPopClient.java
index dcd076ea..72330ba3 100644
--- a/service/src/main/java/cn/qihangerp/service/external/pdd/PddPopClient.java
+++ b/service/src/main/java/cn/qihangerp/service/external/pdd/PddPopClient.java
@@ -23,7 +23,7 @@ import java.util.Map;
  *   <li>{@link #invokeGoodsAdd} — {@code pdd.goods.add}：业务字段全部在表单顶层（{@code sku_list}、{@code carousel_gallery} 等为 JSON 字符串），
  *       <b>无</b> {@code param_json}、<b>无</b> {@code version}</li>
  *   <li>{@link #invokeTopLevelBiz} — 如 {@code pdd.goods.cat.rule.get} 的 {@code cat_id}/{@code goods_id} 等顶层字段</li>
- *   <li>{@link #invokeGoodsImageUpload} — {@code pdd.goods.image.upload}：{@code application/x-www-form-urlencoded}，{@code image} 为 Base64</li>
+ *   <li>{@link #invokeGoodsImageUpload} — {@code pdd.goods.image.upload}：urlencoded，{@code image} 为 {@code data:image/*;base64,} + Base64</li>
  *   <li>{@link #invoke} — 仅当接口要求整包 {@code param_json} 时使用（少数场景）</li>
  * </ul>
  */
@@ -97,9 +97,9 @@ public class PddPopClient {
     }
 
     /**
-     * {@code pdd.goods.image.upload}：与官方 curl/SDK 一致，{@code Content-Type: application/x-www-form-urlencoded}。
-     * <p>开放平台参数 {@code image}：类型 STRING、<b>必填</b>；支持 jpg/jpeg、png 等，<b>须为图片二进制经 Base64 编码后的字符串</b>。
-     * 本方法对下载/读取得到的原始字节使用 {@link Base64#getEncoder()}（标准 Base64，无 {@code data:image/...;base64,} 前缀）。</p>
+     * {@code pdd.goods.image.upload}：{@code application/x-www-form-urlencoded}。
+     * <p>参数 {@code image} 为必填 STRING：常见对接要求为 {@code data:image/jpeg;base64,} 或 {@code data:image/png;base64,}
+     * 后接<strong>标准 Base64</strong>（无换行）。仅传裸 Base64 时网关可能返回「图片格式错误」。</p>
      */
     public String invokeGoodsImageUpload(String gatewayUrl, String clientId, String clientSecret, String accessToken,
                                          byte[] imageBytes) throws Exception {
@@ -109,14 +109,48 @@ public class PddPopClient {
         if (imageBytes == null || imageBytes.length == 0) {
             throw new IllegalArgumentException("image 不能为空");
         }
-        String b64 = Base64.getEncoder().encodeToString(imageBytes);
+        String imageParam = buildPddGoodsImageUploadParam(imageBytes);
         Map<String, String> params = buildBaseParams(clientId, accessToken, "pdd.goods.image.upload", false);
-        params.put("image", b64);
-        String logPayload = "pdd.goods.image.upload image=base64(len=" + b64.length() + ") rawBytes=" + imageBytes.length;
+        params.put("image", imageParam);
+        String logPayload = "pdd.goods.image.upload image=data:*;base64,(totalChars=" + imageParam.length() + ") rawBytes="
+                + imageBytes.length;
         return postSignedAndLog(gatewayUrl, clientId, clientSecret, "pdd.goods.image.upload", params, logPayload,
                 Duration.ofSeconds(180));
     }
 
+    /**
+     * 组装 {@code pdd.goods.image.upload} 的 {@code image} 字段：{@code data:{mime};base64,}{base64}。
+     */
+    static String buildPddGoodsImageUploadParam(byte[] imageBytes) {
+        String mime = guessImageMimeForPddUpload(imageBytes);
+        String b64 = Base64.getEncoder().encodeToString(imageBytes);
+        return "data:" + mime + ";base64," + b64;
+    }
+
+    /** 按文件头识别 MIME；无法识别时按 jpeg 声明（仍可能因非图片内容被平台拒绝）。 */
+    private static String guessImageMimeForPddUpload(byte[] b) {
+        if (b == null || b.length < 12) {
+            return "image/jpeg";
+        }
+        if (b[0] == (byte) 0xFF && b[1] == (byte) 0xD8 && b[2] == (byte) 0xFF) {
+            return "image/jpeg";
+        }
+        if (b[0] == (byte) 0x89 && b[1] == 'P' && b[2] == 'N' && b[3] == 'G') {
+            return "image/png";
+        }
+        if (b[0] == 'G' && b[1] == 'I' && b[2] == 'F') {
+            return "image/gif";
+        }
+        if (b[0] == 'R' && b[1] == 'I' && b[2] == 'F' && b[3] == 'F'
+                && b[8] == 'W' && b[9] == 'E' && b[10] == 'B' && b[11] == 'P') {
+            return "image/webp";
+        }
+        if (b[0] == 'B' && b[1] == 'M') {
+            return "image/bmp";
+        }
+        return "image/jpeg";
+    }
+
     private static Map<String, String> buildBaseParams(String clientId, String accessToken, String type,
                                                          boolean withVersion) {
         long ts = System.currentTimeMillis() / 1000L;