diff --git a/src/main/java/com/ai/da/service/impl/DesignItemServiceImpl.java b/src/main/java/com/ai/da/service/impl/DesignItemServiceImpl.java
index b970b23c..6b9de8dd 100644
--- a/src/main/java/com/ai/da/service/impl/DesignItemServiceImpl.java
+++ b/src/main/java/com/ai/da/service/impl/DesignItemServiceImpl.java
@@ -443,6 +443,15 @@ public class DesignItemServiceImpl extends ServiceImpl<DesignItemMapper, DesignI
             designItemDetail.setGradientString(detail.getGradientString());
 
             designItemDetails.add(designItemDetail);
+
+            // 处理gradientString为null的情况，强制更新为null
+            if (Objects.isNull(detail.getGradientString()) && Objects.nonNull(designItemDetail.getId())) {
+                UpdateWrapper<DesignItemDetail> updateWrapper = new UpdateWrapper<>();
+                updateWrapper.eq("id", designItemDetail.getId());
+                updateWrapper.set("gradient_string", null);
+                updateWrapper.set("update_date", DateUtil.getByTimeZone(timeZone));
+                designItemDetailService.update(null, updateWrapper);
+            }
         });
 
         // 逻辑删除未复用的旧记录