diff --git a/backend/src/main/java/com/designhub/service/AnalyticsService.java b/backend/src/main/java/com/designhub/service/AnalyticsService.java
index a28954a..6523bf9 100644
--- a/backend/src/main/java/com/designhub/service/AnalyticsService.java
+++ b/backend/src/main/java/com/designhub/service/AnalyticsService.java
@@ -1008,8 +1008,21 @@ public class AnalyticsService {
             BigDecimal netB = b.getNetScore() != null ? b.getNetScore() : BigDecimal.ZERO;
             return netB.compareTo(netA);
         });
-        // 按当前负载排序
-        workloadStats.sort((a, b) -> b.getCurrentLoad().compareTo(a.getCurrentLoad()));
+        // 按当前负载排序（null 值排在最后）
+        workloadStats.sort((a, b) -> {
+            Integer loadA = a.getCurrentLoad();
+            Integer loadB = b.getCurrentLoad();
+            if (loadA == null && loadB == null) {
+                return 0;
+            }
+            if (loadA == null) {
+                return 1; // a 排在后面
+            }
+            if (loadB == null) {
+                return -1; // b 排在后面
+            }
+            return loadB.compareTo(loadA); // 降序排序
+        });
         
         // 构建汇总数据
         DesignerPerformanceVO.Summary summary = DesignerPerformanceVO.Summary.builder()
@@ -1302,9 +1315,28 @@ public class AnalyticsService {
         
         // 按预警级别排序（紧急在前）
         warnings.sort((a, b) -> {
-            int levelCompare = "urgent".equals(a.getWarningLevel()) ? -1 : ("urgent".equals(b.getWarningLevel()) ? 1 : 0);
-            if (levelCompare != 0) return levelCompare;
-            return b.getHoursInfo().compareTo(a.getHoursInfo());
+            // 先按预警级别排序：urgent 在前
+            boolean aIsUrgent = "urgent".equals(a.getWarningLevel());
+            boolean bIsUrgent = "urgent".equals(b.getWarningLevel());
+            if (aIsUrgent && !bIsUrgent) {
+                return -1; // a 排在前面
+            }
+            if (!aIsUrgent && bIsUrgent) {
+                return 1; // b 排在前面
+            }
+            // 如果级别相同，按 hoursInfo 降序排序（null 值排在最后）
+            Double hoursA = a.getHoursInfo();
+            Double hoursB = b.getHoursInfo();
+            if (hoursA == null && hoursB == null) {
+                return 0;
+            }
+            if (hoursA == null) {
+                return 1; // a 排在后面
+            }
+            if (hoursB == null) {
+                return -1; // b 排在后面
+            }
+            return Double.compare(hoursB, hoursA); // 降序排序
         });
         
         return warnings;