diff --git a/apps/server/src/bills/bills.controller.ts b/apps/server/src/bills/bills.controller.ts
index e3c04f0..faaaf64 100644
--- a/apps/server/src/bills/bills.controller.ts
+++ b/apps/server/src/bills/bills.controller.ts
@@ -13,6 +13,8 @@ import {
   Req,
 } from '@nestjs/common';
 import { BillsService } from './bills.service';
+import { NotificationsService } from '../notifications/notifications.service';
+import { NotificationType } from '../entities/notification.entity';
 import { BillsExportService } from './bills-export.service';
 import { GenerateBillsDto, UpdateBillStatusDto } from './dto/bill.dto';
 import { JwtAuthGuard } from '../auth/guards/jwt-auth.guard';
@@ -28,6 +30,7 @@ export class BillsController {
     private service: BillsService,
     private exportService: BillsExportService,
     private logService: OperationLogsService,
+    private readonly notificationsService: NotificationsService,
   ) {}
 
   @Post('generate')
@@ -44,6 +47,7 @@ export class BillsController {
       ipAddress,
       userAgent,
     });
+    // TODO: Send notifications for bill_generated — studentId→userId mapping unavailable
     return result;
   }
 
@@ -88,6 +92,7 @@ export class BillsController {
       ipAddress,
       userAgent,
     });
+    // TODO: Send notification for bill_paid — bill.studentId→userId mapping unavailable
     return result;
   }
 
@@ -105,6 +110,7 @@ export class BillsController {
       ipAddress,
       userAgent,
     });
+    // TODO: Send notification for bill_paid (batch) — bill.studentId→userId mapping unavailable
     return result;
   }
 
diff --git a/apps/server/src/bills/bills.module.ts b/apps/server/src/bills/bills.module.ts
index 1ec7595..2da2e6b 100644
--- a/apps/server/src/bills/bills.module.ts
+++ b/apps/server/src/bills/bills.module.ts
@@ -1,4 +1,5 @@
 import { Module } from '@nestjs/common';
+import { NotificationsModule } from '../notifications/notifications.module';
 import { TypeOrmModule } from '@nestjs/typeorm';
 import { Bill } from '../entities/bill.entity';
 import { BillItem } from '../entities/bill-item.entity';
@@ -22,6 +23,7 @@ import { BillsController } from './bills.controller';
       Room,
       Deposit,
     ]),
+    NotificationsModule,
   ],
   controllers: [BillsController],
   providers: [BillsService, BillsExportService],
diff --git a/apps/server/src/classes/classes.controller.ts b/apps/server/src/classes/classes.controller.ts
index 3a647c4..4bb81a2 100644
--- a/apps/server/src/classes/classes.controller.ts
+++ b/apps/server/src/classes/classes.controller.ts
@@ -24,6 +24,8 @@ import { JwtAuthGuard } from '../auth/guards/jwt-auth.guard';
 import { OperationLogsService } from '../operation-logs/operation-logs.service';
 import { extractRequestInfo } from '../common/request-utils';
 import { RequirePermission } from '../auth/decorators/permission.decorator';
+import { NotificationsService } from '../notifications/notifications.service';
+import { NotificationType } from '../entities/notification.entity';
 import * as ExcelJS from 'exceljs';
 
 @UseGuards(JwtAuthGuard)
@@ -32,6 +34,7 @@ export class ClassesController {
   constructor(
     private readonly service: ClassesService,
     private readonly logService: OperationLogsService,
+    private readonly notificationsService: NotificationsService,
   ) {}
 
   @Get()
@@ -170,6 +173,17 @@ export class ClassesController {
       ipAddress,
       userAgent,
     });
+    try {
+      const cls = await this.service.findOne(+id);
+      if (cls.headTeacherId) {
+        void this.notificationsService.create({
+          recipientIds: [cls.headTeacherId],
+          type: NotificationType.CLASS_CHANGE,
+          title: '学员变动',
+          content: `班级新增${result.added}名学生`,
+        });
+      }
+    } catch {}
     return result;
   }
 
@@ -222,6 +236,14 @@ export class ClassesController {
       ipAddress,
       userAgent,
     });
+    try {
+      void this.notificationsService.create({
+        recipientIds: [dto.userId],
+        type: NotificationType.CLASS_CHANGE,
+        title: '班级分配',
+        content: `您已被分配到班级担任${dto.roleType}角色`,
+      });
+    } catch {}
     return result;
   }
 
diff --git a/apps/server/src/classes/classes.module.ts b/apps/server/src/classes/classes.module.ts
index b95f6dc..a99c715 100644
--- a/apps/server/src/classes/classes.module.ts
+++ b/apps/server/src/classes/classes.module.ts
@@ -4,9 +4,10 @@ import { Class, ClassStudent, ClassTeacher } from '../entities';
 import { ClassesService } from './classes.service';
 import { ClassesController } from './classes.controller';
 import { OperationLogsModule } from '../operation-logs/operation-logs.module';
+import { NotificationsModule } from '../notifications/notifications.module';
 
 @Module({
-  imports: [TypeOrmModule.forFeature([Class, ClassStudent, ClassTeacher]), OperationLogsModule],
+  imports: [TypeOrmModule.forFeature([Class, ClassStudent, ClassTeacher]), OperationLogsModule, NotificationsModule],
   controllers: [ClassesController],
   providers: [ClassesService],
   exports: [ClassesService],
diff --git a/apps/server/src/deposits/deposits.controller.ts b/apps/server/src/deposits/deposits.controller.ts
index 3e086da..374b654 100644
--- a/apps/server/src/deposits/deposits.controller.ts
+++ b/apps/server/src/deposits/deposits.controller.ts
@@ -11,6 +11,8 @@ import {
   Request,
 } from '@nestjs/common';
 import { DepositsService } from './deposits.service';
+import { NotificationsService } from '../notifications/notifications.service';
+import { NotificationType } from '../entities/notification.entity';
 import { CreateDepositDto, RefundDepositDto, CreateDepositWithInstallmentsDto } from './dto/deposit.dto';
 import { JwtAuthGuard } from '../auth/guards/jwt-auth.guard';
 import { OperationLogsService } from '../operation-logs/operation-logs.service';
@@ -23,6 +25,7 @@ export class DepositsController {
   constructor(
     private service: DepositsService,
     private logService: OperationLogsService,
+    private readonly notificationsService: NotificationsService,
   ) {}
 
   @Get()
@@ -68,6 +71,7 @@ export class DepositsController {
       ipAddress,
       userAgent,
     });
+    // TODO: Send notification for deposit_due — studentId→userId mapping unavailable
     return result;
   }
 
@@ -111,6 +115,7 @@ export class DepositsController {
       ipAddress,
       userAgent,
     });
+    // TODO: Send notification for deposit_refunded — studentId→userId mapping unavailable
     return result;
   }
 
diff --git a/apps/server/src/deposits/deposits.module.ts b/apps/server/src/deposits/deposits.module.ts
index bcb16b6..545a9d7 100644
--- a/apps/server/src/deposits/deposits.module.ts
+++ b/apps/server/src/deposits/deposits.module.ts
@@ -5,9 +5,10 @@ import { DepositInstallment } from '../entities/deposit-installment.entity';
 import { DepositsService } from './deposits.service';
 import { DepositsController } from './deposits.controller';
 import { OperationLogsModule } from '../operation-logs/operation-logs.module';
+import { NotificationsModule } from '../notifications/notifications.module';
 
 @Module({
-  imports: [TypeOrmModule.forFeature([Deposit, DepositInstallment]), OperationLogsModule],
+  imports: [TypeOrmModule.forFeature([Deposit, DepositInstallment]), OperationLogsModule, NotificationsModule],
   controllers: [DepositsController],
   providers: [DepositsService],
   exports: [DepositsService],
diff --git a/apps/server/src/occupancies/occupancies.controller.ts b/apps/server/src/occupancies/occupancies.controller.ts
index 13cb460..9a2bace 100644
--- a/apps/server/src/occupancies/occupancies.controller.ts
+++ b/apps/server/src/occupancies/occupancies.controller.ts
@@ -16,6 +16,8 @@ import {
 import { FileInterceptor } from '@nestjs/platform-express';
 import type { Response } from 'express';
 import { OccupanciesService } from './occupancies.service';
+import { NotificationsService } from '../notifications/notifications.service';
+import { NotificationType } from '../entities/notification.entity';
 import { CheckInDto, CheckOutDto, TransferRoomDto, BatchCheckOutDto } from './dto/occupancy.dto';
 import { JwtAuthGuard } from '../auth/guards/jwt-auth.guard';
 import { OperationLogsService } from '../operation-logs/operation-logs.service';
@@ -29,6 +31,7 @@ export class OccupanciesController {
   constructor(
     private service: OccupanciesService,
     private logService: OperationLogsService,
+    private readonly notificationsService: NotificationsService,
   ) {}
 
   @Get()
@@ -78,6 +81,7 @@ export class OccupanciesController {
       ipAddress,
       userAgent,
     });
+    // TODO: Send notification for check_in — studentId→userId mapping unavailable
     return result;
   }
 
@@ -96,6 +100,7 @@ export class OccupanciesController {
       ipAddress,
       userAgent,
     });
+    // TODO: Send notification for check_out — studentId→userId mapping unavailable
     return result;
   }
 
diff --git a/apps/server/src/occupancies/occupancies.module.ts b/apps/server/src/occupancies/occupancies.module.ts
index 6cc4320..e583969 100644
--- a/apps/server/src/occupancies/occupancies.module.ts
+++ b/apps/server/src/occupancies/occupancies.module.ts
@@ -7,9 +7,10 @@ import { Deposit } from '../entities/deposit.entity';
 import { OccupanciesService } from './occupancies.service';
 import { OccupanciesController } from './occupancies.controller';
 import { OperationLogsModule } from '../operation-logs/operation-logs.module';
+import { NotificationsModule } from '../notifications/notifications.module';
 
 @Module({
-  imports: [TypeOrmModule.forFeature([Occupancy, Room, Student, Deposit]), OperationLogsModule],
+  imports: [TypeOrmModule.forFeature([Occupancy, Room, Student, Deposit]), OperationLogsModule, NotificationsModule],
   controllers: [OccupanciesController],
   providers: [OccupanciesService],
   exports: [OccupanciesService],
diff --git a/apps/server/src/schedules/schedules.controller.ts b/apps/server/src/schedules/schedules.controller.ts
index 6acedfd..3922305 100644
--- a/apps/server/src/schedules/schedules.controller.ts
+++ b/apps/server/src/schedules/schedules.controller.ts
@@ -20,6 +20,9 @@ import {
 import { JwtAuthGuard } from '../auth/guards/jwt-auth.guard';
 import { OperationLogsService } from '../operation-logs/operation-logs.service';
 import { extractRequestInfo } from '../common/request-utils';
+import { ConflictException } from '@nestjs/common';
+import { NotificationsService } from '../notifications/notifications.service';
+import { NotificationType } from '../entities/notification.entity';
 import { RequirePermission } from '../auth/decorators/permission.decorator';
 
 @UseGuards(JwtAuthGuard)
@@ -28,6 +31,7 @@ export class SchedulesController {
   constructor(
     private readonly service: SchedulesService,
     private readonly logService: OperationLogsService,
+    private readonly notificationsService: NotificationsService,
   ) {}
 
   @Get()
@@ -61,19 +65,39 @@ export class SchedulesController {
   @RequirePermission('schedule:create')
   async create(@Body() dto: CreateScheduleDto, @Request() req: { user?: { id: number; username: string }; headers?: Record<string, string> }) {
     const { ipAddress, userAgent } = extractRequestInfo(req);
-    const result = await this.service.create(dto);
-    await this.logService.log({
-      userId: req.user?.id,
-      username: req.user?.username,
-      module: '排课管理',
-      action: '创建排课',
-      targetId: result.id,
-      targetType: 'class-schedule',
-      detail: `${result.subject} 周${result.weekDay} ${result.startTime}-${result.endTime}`,
-      ipAddress,
-      userAgent,
-    });
-    return result;
+    try {
+      const result = await this.service.create(dto);
+      await this.logService.log({
+        userId: req.user?.id,
+        username: req.user?.username,
+        module: '排课管理',
+        action: '创建排课',
+        targetId: result.id,
+        targetType: 'class-schedule',
+        detail: `${result.subject} 周${result.weekDay} ${result.startTime}-${result.endTime}`,
+        ipAddress,
+        userAgent,
+      });
+      return result;
+    } catch (error) {
+      if (error instanceof ConflictException) {
+        try {
+          const conflicts = await this.service.checkConflict(
+            dto.classroomId, dto.weekDay, dto.startTime, dto.endTime, dto.startDate, dto.endDate,
+          );
+          const teacherIds = [...new Set(conflicts.map(c => c.teacherId).filter(Boolean))];
+          if (teacherIds.length > 0) {
+            void this.notificationsService.create({
+              recipientIds: teacherIds,
+              type: NotificationType.SCHEDULE_CONFLICT,
+              title: '排课冲突',
+              content: `教室${dto.classroomId} 周${dto.weekDay} ${dto.startTime}-${dto.endTime} 与已有排课冲突`,
+            });
+          }
+        } catch {}
+      }
+      throw error;
+    }
   }
 
   @Put(':id')
@@ -84,19 +108,39 @@ export class SchedulesController {
     @Request() req: { user?: { id: number; username: string }; headers?: Record<string, string> },
   ) {
     const { ipAddress, userAgent } = extractRequestInfo(req);
-    const result = await this.service.update(+id, dto);
-    await this.logService.log({
-      userId: req.user?.id,
-      username: req.user?.username,
-      module: '排课管理',
-      action: '编辑排课',
-      targetId: +id,
-      targetType: 'class-schedule',
-      detail: JSON.stringify(dto),
-      ipAddress,
-      userAgent,
-    });
-    return result;
+    try {
+      const result = await this.service.update(+id, dto);
+      await this.logService.log({
+        userId: req.user?.id,
+        username: req.user?.username,
+        module: '排课管理',
+        action: '编辑排课',
+        targetId: +id,
+        targetType: 'class-schedule',
+        detail: JSON.stringify(dto),
+        ipAddress,
+        userAgent,
+      });
+      return result;
+    } catch (error) {
+      if (error instanceof ConflictException) {
+        try {
+          const conflicts = await this.service.checkConflict(
+            dto.classroomId ?? 0, dto.weekDay ?? 0, dto.startTime ?? '', dto.endTime ?? '', dto.startDate ?? '', dto.endDate ?? '',
+          );
+          const teacherIds = [...new Set(conflicts.map(c => c.teacherId).filter(Boolean))];
+          if (teacherIds.length > 0) {
+            void this.notificationsService.create({
+              recipientIds: teacherIds,
+              type: NotificationType.SCHEDULE_CONFLICT,
+              title: '排课冲突',
+              content: `教室${dto.classroomId} 周${dto.weekDay} ${dto.startTime}-${dto.endTime} (更新) 与已有排课冲突`,
+            });
+          }
+        } catch {}
+      }
+      throw error;
+    }
   }
 
   @Delete(':id')
diff --git a/apps/server/src/schedules/schedules.module.ts b/apps/server/src/schedules/schedules.module.ts
index c9a7b03..fa6d96d 100644
--- a/apps/server/src/schedules/schedules.module.ts
+++ b/apps/server/src/schedules/schedules.module.ts
@@ -4,9 +4,10 @@ import { ClassSchedule } from '../entities';
 import { SchedulesService } from './schedules.service';
 import { SchedulesController } from './schedules.controller';
 import { OperationLogsModule } from '../operation-logs/operation-logs.module';
+import { NotificationsModule } from '../notifications/notifications.module';
 
 @Module({
-  imports: [TypeOrmModule.forFeature([ClassSchedule]), OperationLogsModule],
+  imports: [TypeOrmModule.forFeature([ClassSchedule]), OperationLogsModule, NotificationsModule],
   controllers: [SchedulesController],
   providers: [SchedulesService],
   exports: [SchedulesService],