diff --git a/epmet-commons/epmet-commons-tools/src/main/java/com/epmet/commons/tools/exception/EpmetErrorCode.java b/epmet-commons/epmet-commons-tools/src/main/java/com/epmet/commons/tools/exception/EpmetErrorCode.java
index ed274b2c28..6a66e1ae71 100644
--- a/epmet-commons/epmet-commons-tools/src/main/java/com/epmet/commons/tools/exception/EpmetErrorCode.java
+++ b/epmet-commons/epmet-commons-tools/src/main/java/com/epmet/commons/tools/exception/EpmetErrorCode.java
@@ -256,6 +256,7 @@ public enum EpmetErrorCode {
 	RESI_IC_NAT(8925,"已存在记录，请联系社区工作人员修改"),
 	IC_MOVE_IN(8926,"居民信息中房屋信息与当前选择房屋不一致，是否更新？"),
 	NOT_REGEIST_RESI(8927,"未注册居民"),
+	UNIT_EXIST_HOUSES_ERROR(8928,"单元下存在房屋，不可修改单元数"),
 
 
 	//通用错误码 start
diff --git a/epmet-module/gov-org/gov-org-server/src/main/java/com/epmet/dao/IcBuildingUnitDao.java b/epmet-module/gov-org/gov-org-server/src/main/java/com/epmet/dao/IcBuildingUnitDao.java
index 69465df911..147f25f7d2 100644
--- a/epmet-module/gov-org/gov-org-server/src/main/java/com/epmet/dao/IcBuildingUnitDao.java
+++ b/epmet-module/gov-org/gov-org-server/src/main/java/com/epmet/dao/IcBuildingUnitDao.java
@@ -20,6 +20,9 @@ package com.epmet.dao;
 import com.epmet.commons.mybatis.dao.BaseDao;
 import com.epmet.entity.IcBuildingUnitEntity;
 import org.apache.ibatis.annotations.Mapper;
+import org.apache.ibatis.annotations.Param;
+
+import java.util.List;
 
 /**
  * 楼栋单元信息
@@ -29,5 +32,22 @@ import org.apache.ibatis.annotations.Mapper;
  */
 @Mapper
 public interface IcBuildingUnitDao extends BaseDao<IcBuildingUnitEntity> {
-	
+
+    /**
+     * Desc: 根据楼栋ID获取单元IDs
+     * @param buildingId
+     * @param size
+     * @author zxc
+     * @date 2022/5/31 15:46
+     */
+    List<String> getUnitIdByBuildingId(@Param("buildingId")String buildingId,@Param("size")Integer size);
+
+    /**
+     * Desc: 删除单元
+     * @param ids
+     * @author zxc
+     * @date 2022/5/31 16:04
+     */
+    void delUnit(@Param("ids")List<String> ids);
+
 }
\ No newline at end of file
diff --git a/epmet-module/gov-org/gov-org-server/src/main/java/com/epmet/dao/IcHouseDao.java b/epmet-module/gov-org/gov-org-server/src/main/java/com/epmet/dao/IcHouseDao.java
index e1cb4de562..d428631ad5 100644
--- a/epmet-module/gov-org/gov-org-server/src/main/java/com/epmet/dao/IcHouseDao.java
+++ b/epmet-module/gov-org/gov-org-server/src/main/java/com/epmet/dao/IcHouseDao.java
@@ -102,4 +102,12 @@ public interface IcHouseDao extends BaseDao<IcHouseEntity> {
      */
     HouseAgencyInfoResultDTO getHouseAgencyInfo(@Param("houseId") String houseId);
 
+    /**
+     * Desc: 获取单元下的房屋数
+     * @param unitIds
+     * @author zxc
+     * @date 2022/5/31 15:53
+     */
+    Integer getHouseCountByUnitIds(@Param("unitIds")List<String> unitIds);
+
 }
diff --git a/epmet-module/gov-org/gov-org-server/src/main/java/com/epmet/service/impl/BuildingServiceImpl.java b/epmet-module/gov-org/gov-org-server/src/main/java/com/epmet/service/impl/BuildingServiceImpl.java
index ceab6ed43d..c1863e5cd0 100644
--- a/epmet-module/gov-org/gov-org-server/src/main/java/com/epmet/service/impl/BuildingServiceImpl.java
+++ b/epmet-module/gov-org/gov-org-server/src/main/java/com/epmet/service/impl/BuildingServiceImpl.java
@@ -454,7 +454,20 @@ public class BuildingServiceImpl implements BuildingService {
         Integer unit = icBuilding.getTotalUnitNum();
         if (nowUnit < unit) {
             //如果小于，判断是否存在房屋，如果存在就提示不能更改
-            throw new EpmetException(EpmetErrorCode.ORG_EDIT_FAILED.getCode(), EpmetErrorCode.ORG_EDIT_FAILED.getMsg(), "暂不支持单元号减小");
+            /**
+             * 校验规则，单元号倒序，校验（原来的单元数 - 现在单元数）个单元下是不是存在房屋，存在房屋不能更新
+             * 2022-05-31修改逻辑，可以修改变小，先去校验,单元下存在房屋就报错，不存在，删除对应单元，更新楼栋单元数
+             */
+            Integer size = unit - nowUnit;
+            List<String> ids = icBuildingUnitDao.getUnitIdByBuildingId(formDTO.getBuildingId(), size);
+            if (!CollectionUtils.isEmpty(ids)){
+                Integer houseCount = icHouseDao.getHouseCountByUnitIds(ids);
+                if (houseCount.compareTo(NumConstant.ZERO) != NumConstant.ZERO){
+                    throw new EpmetException(EpmetErrorCode.UNIT_EXIST_HOUSES_ERROR.getCode());
+                }
+                icBuildingUnitDao.delUnit(ids);
+            }
+//            throw new EpmetException(EpmetErrorCode.ORG_EDIT_FAILED.getCode(), EpmetErrorCode.ORG_EDIT_FAILED.getMsg(), "暂不支持单元号减小");
         } else {
             //新增单元
             List<OptionResultDTO> units = icBuildingUnitService.getUnitOptions(icBuilding.getId());
diff --git a/epmet-module/gov-org/gov-org-server/src/main/resources/mapper/IcBuildingUnitDao.xml b/epmet-module/gov-org/gov-org-server/src/main/resources/mapper/IcBuildingUnitDao.xml
index 0ee38da368..09f334b42d 100644
--- a/epmet-module/gov-org/gov-org-server/src/main/resources/mapper/IcBuildingUnitDao.xml
+++ b/epmet-module/gov-org/gov-org-server/src/main/resources/mapper/IcBuildingUnitDao.xml
@@ -3,19 +3,20 @@
 
 <mapper namespace="com.epmet.dao.IcBuildingUnitDao">
 
-    <resultMap type="com.epmet.entity.IcBuildingUnitEntity" id="icBuildingUnitMap">
-        <result property="id" column="ID"/>
-        <result property="customerId" column="CUSTOMER_ID"/>
-        <result property="buildingId" column="BUILDING_ID"/>
-        <result property="unitNum" column="UNIT_NUM"/>
-        <result property="unitName" column="UNIT_NAME"/>
-        <result property="delFlag" column="DEL_FLAG"/>
-        <result property="revision" column="REVISION"/>
-        <result property="createdBy" column="CREATED_BY"/>
-        <result property="createdTime" column="CREATED_TIME"/>
-        <result property="updatedBy" column="UPDATED_BY"/>
-        <result property="updatedTime" column="UPDATED_TIME"/>
-    </resultMap>
+    <!-- 删除单元 -->
+    <update id="delUnit">
+        UPDATE ic_building_unit
+        SET DEL_FLAG = '1',
+            UPDATED_TIME = NOW()
+        WHERE ID IN (
+            <foreach collection="ids" item="id" separator=",">#{id}</foreach>
+            )
+    </update>
+
+    <!-- 根据楼栋ID获取单元IDs -->
+    <select id="getUnitIdByBuildingId" resultType="java.lang.String">
+        SELECT ID FROM ic_building_unit WHERE DEL_FLAG = '0' AND BUILDING_ID = #{buildingId} ORDER BY UNIT_NUM+0 DESC LIMIT #{size}
+    </select>
 
 
 </mapper>
\ No newline at end of file
diff --git a/epmet-module/gov-org/gov-org-server/src/main/resources/mapper/IcHouseDao.xml b/epmet-module/gov-org/gov-org-server/src/main/resources/mapper/IcHouseDao.xml
index 7df81d921a..a8222a88bb 100644
--- a/epmet-module/gov-org/gov-org-server/src/main/resources/mapper/IcHouseDao.xml
+++ b/epmet-module/gov-org/gov-org-server/src/main/resources/mapper/IcHouseDao.xml
@@ -380,4 +380,11 @@
         WHERE h.ID = #{houseId}
     </select>
 
+    <!-- 获取单元下的房屋数 -->
+    <select id="getHouseCountByUnitIds" resultType="java.lang.Integer">
+        SELECT COUNT(ID) FROM ic_house WHERE DEL_FLAG = '0' AND BUILDING_UNIT_ID IN (
+            <foreach collection="unitIds" item="id" separator=",">#{id}</foreach>
+            )
+    </select>
+
 </mapper>