diff --git a/backend/src/main/java/com/designhub/service/TaskService.java b/backend/src/main/java/com/designhub/service/TaskService.java
index 83bb741..f076b91 100644
--- a/backend/src/main/java/com/designhub/service/TaskService.java
+++ b/backend/src/main/java/com/designhub/service/TaskService.java
@@ -114,10 +114,10 @@ public class TaskService {
                 Long firstTypeId = Long.parseLong(typeIds[0].trim());
                 var firstType = configService.getDemandTypeById(firstTypeId);
                 int totalScore = firstType.getUnitScore().multiply(BigDecimal.valueOf(task.getQuantity())).intValue();
-                int totalHours = firstType.getEstimatedHours() != null ? firstType.getEstimatedHours() * task.getQuantity() : 0;
+                BigDecimal totalHours = firstType.getEstimatedHours() != null ? firstType.getEstimatedHours().multiply(BigDecimal.valueOf(task.getQuantity())) : BigDecimal.ZERO;
                 
                 task.setScore(totalScore);
-                task.setEstimatedHours(BigDecimal.valueOf(totalHours));
+                task.setEstimatedHours(totalHours);
                 
                 // 兼容性：同时保存第一个类型到task_type_id
                 task.setTaskTypeId(firstTypeId);
@@ -133,10 +133,10 @@ public class TaskService {
                 
                 // 计算总积分和工时
                 int totalScore = demandType.getUnitScore().multiply(BigDecimal.valueOf(task.getQuantity())).intValue();
-                int totalHours = demandType.getEstimatedHours() != null ? demandType.getEstimatedHours() * task.getQuantity() : 0;
+                BigDecimal totalHours = demandType.getEstimatedHours() != null ? demandType.getEstimatedHours().multiply(BigDecimal.valueOf(task.getQuantity())) : BigDecimal.ZERO;
                 
                 task.setScore(totalScore);
-                task.setEstimatedHours(BigDecimal.valueOf(totalHours));
+                task.setEstimatedHours(totalHours);
                 
                 // 自动填充taskTypeIds字段
                 task.setTaskTypeIds(String.valueOf(task.getTaskTypeId()));
@@ -255,7 +255,7 @@ public class TaskService {
             }
 
             int itemScore = demandType.getUnitScore().multiply(BigDecimal.valueOf(itemDto.getQuantity())).intValue();
-            double itemHours = demandType.getEstimatedHours() != null ? demandType.getEstimatedHours() * itemDto.getQuantity() : 0;
+            double itemHours = demandType.getEstimatedHours() != null ? demandType.getEstimatedHours().multiply(BigDecimal.valueOf(itemDto.getQuantity())).doubleValue() : 0;
 
             totalScore += itemScore;
             totalHours += itemHours;
@@ -395,7 +395,7 @@ public class TaskService {
             item.setQuantity(itemDto.getQuantity());
             item.setUnitScore(demandType.getUnitScore().intValue());
             item.setTotalScore(demandType.getUnitScore().multiply(BigDecimal.valueOf(itemDto.getQuantity())).intValue());
-            item.setEstimatedHours(BigDecimal.valueOf(demandType.getEstimatedHours() != null ? demandType.getEstimatedHours() * itemDto.getQuantity() : 0));
+            item.setEstimatedHours(demandType.getEstimatedHours() != null ? demandType.getEstimatedHours().multiply(BigDecimal.valueOf(itemDto.getQuantity())) : BigDecimal.ZERO);
             item.setSortOrder(i + 1); // 恢复真实的排序号
             item.setProgress(0);