diff --git a/backend/src/main/java/com/designhub/service/AnalyticsService.java b/backend/src/main/java/com/designhub/service/AnalyticsService.java
index 3f1a29f..7dc6f32 100644
--- a/backend/src/main/java/com/designhub/service/AnalyticsService.java
+++ b/backend/src/main/java/com/designhub/service/AnalyticsService.java
@@ -301,44 +301,24 @@ public class AnalyticsService {
     }
 
     /**
-     * 构建类型分布
+     * 构建类型分布（按任务子类型分组）
      */
     private List<DemandStatisticsVO.TypeDistribution> buildTypeDistribution(List<Task> tasks) {
-        // 优先使用 taskTypeId，如果为空则使用 demandTypeId
-        Map<Long, List<Task>> tasksByType = tasks.stream()
-            .filter(t -> t.getTaskTypeId() != null || t.getDemandTypeId() != null)
-            .collect(Collectors.groupingBy(t -> {
-                if (t.getTaskTypeId() != null) {
-                    return t.getTaskTypeId();
-                }
-                return t.getDemandTypeId();
-            }));
+        // 按任务子类型（taskSubType）分组
+        Map<String, List<Task>> tasksBySubType = tasks.stream()
+            .filter(t -> t.getTaskSubType() != null && !t.getTaskSubType().trim().isEmpty())
+            .collect(Collectors.groupingBy(t -> t.getTaskSubType()));
 
         int totalTasks = tasks.size();
         List<DemandStatisticsVO.TypeDistribution> distribution = new ArrayList<>();
 
-        // 预加载所有任务类型名称
-        Map<Long, String> typeNameMap = new HashMap<>();
-        for (Long typeId : tasksByType.keySet()) {
-            try {
-                DemandType demandType = demandTypeMapper.selectById(typeId);
-                if (demandType != null) {
-                    typeNameMap.put(typeId, demandType.getName());
-                } else {
-                    typeNameMap.put(typeId, "未知类型");
-                }
-            } catch (Exception e) {
-                typeNameMap.put(typeId, "类型" + typeId);
-            }
-        }
-
-        for (Map.Entry<Long, List<Task>> entry : tasksByType.entrySet()) {
-            List<Task> typeTasks = entry.getValue();
-            int count = typeTasks.size();
+        for (Map.Entry<String, List<Task>> entry : tasksBySubType.entrySet()) {
+            List<Task> subTypeTasks = entry.getValue();
+            int count = subTypeTasks.size();
             double percentage = totalTasks > 0 ? (double) count / totalTasks * 100 : 0.0;
             
             // 优先使用 scoreReward，其次使用 score
-            BigDecimal totalScore = typeTasks.stream()
+            BigDecimal totalScore = subTypeTasks.stream()
                 .map(t -> {
                     if (t.getScoreReward() != null && t.getScoreReward().compareTo(BigDecimal.ZERO) > 0) {
                         return t.getScoreReward();
@@ -347,10 +327,10 @@ public class AnalyticsService {
                 })
                 .reduce(BigDecimal.ZERO, BigDecimal::add);
 
-            String typeName = typeNameMap.getOrDefault(entry.getKey(), "类型" + entry.getKey());
+            String subTypeName = entry.getKey();
 
             distribution.add(DemandStatisticsVO.TypeDistribution.builder()
-                .typeName(typeName)
+                .typeName(subTypeName)
                 .count(count)
                 .percentage(percentage)
                 .totalScore(totalScore)