diff --git a/backend/roomroot-jwgl/src/main/java/com/roomroot/jwgl/service/impl/ClassRoomServiceImpl.java b/backend/roomroot-jwgl/src/main/java/com/roomroot/jwgl/service/impl/ClassRoomServiceImpl.java
index 386525833..3bafb1920 100644
--- a/backend/roomroot-jwgl/src/main/java/com/roomroot/jwgl/service/impl/ClassRoomServiceImpl.java
+++ b/backend/roomroot-jwgl/src/main/java/com/roomroot/jwgl/service/impl/ClassRoomServiceImpl.java
@@ -6,6 +6,7 @@ import com.roomroot.common.utils.StringUtils;
 import com.roomroot.jwgl.entity.JSB;
 import com.roomroot.jwgl.mapper.ClassRoomMapper;
 import com.roomroot.jwgl.service.ClassRoomService;
+import com.roomroot.jwgl.unit.BusinessException;
 import com.roomroot.jwgl.unit.PageQuery;
 import com.roomroot.jwgl.unit.PageResult;
 import com.roomroot.jwgl.utils.UuidUtil;
@@ -27,11 +28,17 @@ public class ClassRoomServiceImpl implements ClassRoomService {
     public void add(JSB jsb) {
         jsb.setId(UuidUtil.getUUID());
         jsb.setDelFlag(0);
-        // 教室编号为非空列：留空时按现有最大数字编号 +1 自动生成
+        // 教室编号为非空列：留空时按现有最大数字编号 +1 自动生成；手填时校验唯一，避免按编号查询出现多行
         if (StringUtils.isEmpty(jsb.getJsbh())) {
             jsb.setJsbh(nextJsbh());
         } else {
             jsb.setJsbh(jsb.getJsbh().trim());
+            Long dup = jsbMapper.selectCount(new LambdaQueryWrapper<JSB>()
+                    .eq(JSB::getJsbh, jsb.getJsbh())
+                    .eq(JSB::getDelFlag, 0));
+            if (dup != null && dup > 0) {
+                throw new BusinessException("教室编号已存在：" + jsb.getJsbh());
+            }
         }
         jsbMapper.insert(jsb);
     }
diff --git a/backend/roomroot-jwgl/src/main/java/com/roomroot/jwgl/service/impl/ElectiveServiceImpl.java b/backend/roomroot-jwgl/src/main/java/com/roomroot/jwgl/service/impl/ElectiveServiceImpl.java
index b4eaf3243..39e825e10 100644
--- a/backend/roomroot-jwgl/src/main/java/com/roomroot/jwgl/service/impl/ElectiveServiceImpl.java
+++ b/backend/roomroot-jwgl/src/main/java/com/roomroot/jwgl/service/impl/ElectiveServiceImpl.java
@@ -407,7 +407,12 @@ public class ElectiveServiceImpl implements ElectiveService {
         }
         JSB room = classRoomMapper.selectById(zyjsbh);
         if (room == null) {
-            room = classRoomMapper.selectOne(new LambdaQueryWrapper<JSB>().eq(JSB::getJsbh, zyjsbh));
+            // 教室编号历史上可能出现重复行，取第一条避免 selectOne 多结果异常
+            List<JSB> rooms = classRoomMapper.selectList(new LambdaQueryWrapper<JSB>()
+                    .eq(JSB::getJsbh, zyjsbh)
+                    .eq(JSB::getDelFlag, 0)
+                    .last("LIMIT 1"));
+            room = rooms.isEmpty() ? null : rooms.get(0);
         }
         return room == null ? null : room.getJsmc();
     }