diff --git a/src/main/java/com/gxwebsoft/gxmu/mapper/ClassInfoMapper.java b/src/main/java/com/gxwebsoft/gxmu/mapper/ClassInfoMapper.java
index 8a08a19..cb3e96e 100644
--- a/src/main/java/com/gxwebsoft/gxmu/mapper/ClassInfoMapper.java
+++ b/src/main/java/com/gxwebsoft/gxmu/mapper/ClassInfoMapper.java
@@ -26,4 +26,15 @@ public interface ClassInfoMapper extends BaseMapper<ClassInfo> {
      */
     int batchUpsert(@Param("list") List<ClassInfo> list);
 
+    /**
+     * 按学生名册回填班级人数（学生同步末尾调用）。
+     *
+     * <p>平台 BJRS 对新生班级返回空，只能本地按 {@code gxmu_student.class_id} 统计兜底。
+     * 只补为空或 0 的班级，平台有值时不覆盖。
+     *
+     * @param tenantId 租户ID
+     * @return 更新行数
+     */
+    int refreshStudentCountFromRoster(@Param("tenantId") int tenantId);
+
 }
diff --git a/src/main/java/com/gxwebsoft/gxmu/mapper/xml/ClassInfoMapper.xml b/src/main/java/com/gxwebsoft/gxmu/mapper/xml/ClassInfoMapper.xml
index 3ac3406..7e7f165 100644
--- a/src/main/java/com/gxwebsoft/gxmu/mapper/xml/ClassInfoMapper.xml
+++ b/src/main/java/com/gxwebsoft/gxmu/mapper/xml/ClassInfoMapper.xml
@@ -7,6 +7,12 @@
       ON DUPLICATE KEY UPDATE 里只列「平台权威字段」(docs/adr/0005)：
       sort_number / counselor_phone 属人工维护，同步不触碰；create_time 不重复刷新。
       幂等键是 uk_gxmu_class_code(tenant_id, class_code)。
+
+      counselor_name / student_count 用 COALESCE 保住存量：平台对 2025 级起的班级
+      不返回 BJRS、对 2026 级连 FDYH 都不返回（实测 2026-09-15 那批 1584 条里
+      2025 级 148 条全无人数、2026 级 152 条两项全空）。若照旧写 VALUES()，
+      每晚同步都会把这些列刷成 NULL，人工补录的辅导员和学生人数也就一并清掉了。
+      平台有值时仍以平台为准，只有平台给空才保留原值。
     -->
     <insert id="batchUpsert">
         INSERT INTO gxmu_class (
@@ -26,12 +32,40 @@
             class_name = VALUES(class_name),
             college_id = VALUES(college_id),
             grade_year = VALUES(grade_year),
-            counselor_name = VALUES(counselor_name),
-            student_count = VALUES(student_count),
+            counselor_name = COALESCE(VALUES(counselor_name), counselor_name),
+            student_count = COALESCE(VALUES(student_count), student_count),
             status = VALUES(status),
             remark = VALUES(remark),
             update_time = VALUES(update_time),
             deleted = VALUES(deleted)
     </insert>
 
+    <!--
+      按学生名册回填班级人数。
+
+      平台的 BJRS(班级人数) 是教务口径，实测与「本班在册学生数」基本吻合
+      （2020-2024 级逐班比对，平均误差 0.5~2.7 人），但新生班级一律返回空。
+      学生同步写完后用它兜底：只补「为空或 0」的班级，平台有值时不覆盖，
+      名册里查不到学生（s.n 为空）的班级也不动，避免每次同步都刷 update_time。
+    -->
+    <update id="refreshStudentCountFromRoster">
+        UPDATE gxmu_class c
+        LEFT JOIN (
+            SELECT class_id, COUNT(*) AS n
+            FROM gxmu_student
+            WHERE tenant_id = #{tenantId}
+              AND deleted = 0
+              AND class_id IS NOT NULL
+            GROUP BY class_id
+        ) s ON s.class_id = c.id
+        SET c.student_count = s.n,
+            c.update_time = NOW()
+        WHERE c.tenant_id = #{tenantId}
+          AND c.deleted = 0
+          AND c.class_code IS NOT NULL
+          AND (c.student_count IS NULL OR c.student_count = 0)
+          AND s.n IS NOT NULL
+          AND s.n &gt; 0
+    </update>
+
 </mapper>
diff --git a/src/main/java/com/gxwebsoft/gxmu/openplat/SyncSupport.java b/src/main/java/com/gxwebsoft/gxmu/openplat/SyncSupport.java
index 2375578..9277116 100644
--- a/src/main/java/com/gxwebsoft/gxmu/openplat/SyncSupport.java
+++ b/src/main/java/com/gxwebsoft/gxmu/openplat/SyncSupport.java
@@ -165,6 +165,22 @@ public class SyncSupport {
         }
     }
 
+    /**
+     * 按学生名册回填班级人数。
+     *
+     * <p>平台的 BJRS 对 2025 级起的班级一律返回空（实测 2025 级 148 个班全空），
+     * 只能拿刚写完的名册按 class_id 统计兜底，否则班级管理页的学生人数永远为空。
+     *
+     * @return 更新行数
+     */
+    public int refreshClassStudentCounts() {
+        int updated = classInfoMapper.refreshStudentCountFromRoster(OpenplatSyncConstants.TENANT_ID);
+        if (updated > 0) {
+            logger.warn("班级人数回填: 平台未给出人数的 {} 个班级已按学生名册补上", updated);
+        }
+        return updated;
+    }
+
     /**
      * 分批写入部门
      */
diff --git a/src/main/java/com/gxwebsoft/gxmu/openplat/sync/StudentSyncHandler.java b/src/main/java/com/gxwebsoft/gxmu/openplat/sync/StudentSyncHandler.java
index 5ca5fc6..b6c3d8c 100644
--- a/src/main/java/com/gxwebsoft/gxmu/openplat/sync/StudentSyncHandler.java
+++ b/src/main/java/com/gxwebsoft/gxmu/openplat/sync/StudentSyncHandler.java
@@ -111,6 +111,8 @@ public class StudentSyncHandler {
 
         int deactivated = support.deactivateMissingStudents(existingHash.keySet(), incoming);
         result.setSkipCount(deactivated);
+        // 班级同步（本批更早执行）拿到的 BJRS 对新生班级一律为空，这里按刚写完的名册补上
+        support.refreshClassStudentCounts();
         logger.warn("学生同步完成: 平台 {} 人, 实际写入 {} 行, 未变更跳过 {} 行, 停用 {} 行, 失败 {} 条",
                 merged.size(), changed.size(), merged.size() - changed.size(),
                 deactivated, result.getFailCount());