diff --git a/src/main/java/com/yunhai/bschclassmanage/service/impl/com/ComSchTreeService.java b/src/main/java/com/yunhai/bschclassmanage/service/impl/com/ComSchTreeService.java
index 9e8e135..303175c 100644
--- a/src/main/java/com/yunhai/bschclassmanage/service/impl/com/ComSchTreeService.java
+++ b/src/main/java/com/yunhai/bschclassmanage/service/impl/com/ComSchTreeService.java
@@ -1152,7 +1152,7 @@ public class ComSchTreeService implements IComSchTreeService {
 
         // 高职学制长度（按学校专业最大学制，与 getHigherSchGradeClassTree 保持一致；无则默认3）
         Integer majorLeng = schDicMajorsRepository.findMaxSchsystemLengBySchId(schId).orElse(0);
-        if (majorLeng == null || majorLeng <= 0) {
+        if (majorLeng <= 0) {
             majorLeng = 3;
         }
 
@@ -1169,7 +1169,14 @@ public class ComSchTreeService implements IComSchTreeService {
                 .collect(Collectors.groupingBy(SchClass::getEnrollYear));
 
         // 4. 确定年份范围
-        Integer currentYear = baseYearTermService.getNowYearTerm().getYear();
+        // getNowYearTerm 在"当前时间不在任何学年区间"时抛 DException，此处降级为返回空树，避免 500
+        Integer currentYear;
+        try {
+            currentYear = baseYearTermService.getNowYearTerm().getYear();
+        } catch (DException e) {
+            root.setChildren(Collections.emptyList());
+            return root;
+        }
         Integer minYear = classByYear.keySet().stream().min(Integer::compareTo).orElse(null);
         if (minYear == null) {
             root.setChildren(Collections.emptyList());