diff --git a/src/constants/error-code.constant.ts b/src/constants/error-code.constant.ts
index 95af623..3b381c2 100644
--- a/src/constants/error-code.constant.ts
+++ b/src/constants/error-code.constant.ts
@@ -45,5 +45,9 @@ export enum ErrorEnum {
   // OSS相关
   OSS_FILE_OR_DIR_EXIST = '1401:当前创建的文件或目录已存在',
   OSS_NO_OPERATION_REQUIRED = '1402:无需操作',
-  OSS_EXCEE_MAXIMUM_QUANTITY = '1403:已超出支持的最大处理数量'
+  OSS_EXCEE_MAXIMUM_QUANTITY = '1403:已超出支持的最大处理数量',
+
+  // Storage相关
+  STORAGE_NOT_FOUND = '1404:文件不存在,请重试',
+  STORAGE_REFRENCE_EXISTS = '1405:文件存在关联,无法删除,请先找到该文件关联的业务解除关联。'
 }
diff --git a/src/modules/contract/contract.controller.ts b/src/modules/contract/contract.controller.ts
index 5bdc005..a3e716f 100644
--- a/src/modules/contract/contract.controller.ts
+++ b/src/modules/contract/contract.controller.ts
@@ -66,4 +66,12 @@ export class ContractController {
   async delete(@IdParam() id: number): Promise<void> {
     await this.contractService.delete(id);
   }
+
+  @Put('unlink-attachments/:id')
+  @ApiOperation({ summary: '附件解除关联' })
+  @Perm(permissions.UPDATE)
+  async unlinkAttachments(@IdParam() id: number, @Body() {fileIds}: ContractUpdateDto): Promise<void> {
+    await this.contractService.unlinkAttachments(id, fileIds);
+  }
+
 }
diff --git a/src/modules/contract/contract.dto.ts b/src/modules/contract/contract.dto.ts
index 057ea88..9b4ca8b 100644
--- a/src/modules/contract/contract.dto.ts
+++ b/src/modules/contract/contract.dto.ts
@@ -9,10 +9,10 @@ import {
   IsOptional,
   IsString,
   Matches,
-  MinLength,
-  
+  MinLength
 } from 'class-validator';
 import { PagerDto } from '~/common/dto/pager.dto';
+import { Storage } from '../tools/storage/storage.entity';
 
 export class ContractDto {
   @ApiProperty({ description: '合同编号' })
@@ -47,9 +47,16 @@ export class ContractDto {
   @ApiProperty({ description: '审核状态(字典)' })
   @IsIn([0, 1, 2])
   status: number;
+
+  @ApiProperty({ description: '附件' })
+  files: Storage[];
 }
 
-export class ContractUpdateDto extends PartialType(ContractDto) {}
+export class ContractUpdateDto extends PartialType(ContractDto) {
+  @ApiProperty({ description: '附件' })
+  @IsArray({})
+  fileIds: number[];
+}
 export class ContractQueryDto extends IntersectionType(
   PagerDto<ContractDto>,
   PartialType(ContractDto)
diff --git a/src/modules/contract/contract.entity.ts b/src/modules/contract/contract.entity.ts
index 979533d..afdb5cf 100644
--- a/src/modules/contract/contract.entity.ts
+++ b/src/modules/contract/contract.entity.ts
@@ -1,6 +1,7 @@
 import { ApiHideProperty, ApiProperty } from '@nestjs/swagger';
 import { Column, Entity, JoinTable, ManyToMany, Relation } from 'typeorm';
 import { CommonEntity } from '~/common/entity/common.entity';
+import { Storage } from '../tools/storage/storage.entity';
 
 @Entity({ name: 'contract' })
 export class ContractEntity extends CommonEntity {
@@ -41,4 +42,12 @@ export class ContractEntity extends CommonEntity {
   @Column({ name: 'status', type: 'tinyint', default: 0, comment: '审核状态(字典)' })
   @ApiProperty({ description: '审核状态：0待审核，1同意，2.不同意(字典)' })
   status: number;
+
+  @ManyToMany(() => Storage, storage => storage.contracts)
+  @JoinTable({
+    name: 'contract_storage',
+    joinColumn: { name: 'contract_id', referencedColumnName: 'id' },
+    inverseJoinColumn: { name: 'file_id', referencedColumnName: 'id' }
+  })
+  files: Relation<Storage[]>;
 }
diff --git a/src/modules/contract/contract.module.ts b/src/modules/contract/contract.module.ts
index 46dfda5..d5eabe8 100644
--- a/src/modules/contract/contract.module.ts
+++ b/src/modules/contract/contract.module.ts
@@ -3,9 +3,10 @@ import { ContractController } from './contract.controller';
 import { ContractService } from './contract.service';
 import { TypeOrmModule } from '@nestjs/typeorm';
 import { ContractEntity } from './contract.entity';
+import { StorageModule } from '../tools/storage/storage.module';
 
 @Module({
-  imports: [TypeOrmModule.forFeature([ContractEntity])],
+  imports: [TypeOrmModule.forFeature([ContractEntity]), StorageModule],
   controllers: [ContractController],
   providers: [ContractService]
 })
diff --git a/src/modules/contract/contract.service.ts b/src/modules/contract/contract.service.ts
index 6eafc10..b28eae9 100644
--- a/src/modules/contract/contract.service.ts
+++ b/src/modules/contract/contract.service.ts
@@ -1,17 +1,23 @@
 import { Injectable } from '@nestjs/common';
-import { InjectRepository } from '@nestjs/typeorm';
+import { InjectEntityManager, InjectRepository } from '@nestjs/typeorm';
 import { ContractEntity } from './contract.entity';
-import { Like, Repository } from 'typeorm';
-import { ContractDto, ContractQueryDto } from './contract.dto';
+import { EntityManager, Like, Repository } from 'typeorm';
+import { ContractDto, ContractQueryDto, ContractUpdateDto } from './contract.dto';
 import { Pagination } from '~/helper/paginate/pagination';
 import { isNumber } from 'lodash';
 import { paginate } from '~/helper/paginate';
+import { Storage } from '../tools/storage/storage.entity';
+import { BusinessException } from '~/common/exceptions/biz.exception';
+import { ErrorEnum } from '~/constants/error-code.constant';
 
 @Injectable()
 export class ContractService {
   constructor(
+    @InjectEntityManager() private entityManager: EntityManager,
     @InjectRepository(ContractEntity)
-    private contractRepository: Repository<ContractEntity>
+    private contractRepository: Repository<ContractEntity>,
+    @InjectRepository(Storage)
+    private storageRepository: Repository<Storage>
   ) {}
   /**
    * 列举所有角色：除去超级管理员
@@ -24,12 +30,16 @@ export class ContractService {
     type,
     status
   }: ContractQueryDto): Promise<Pagination<ContractEntity>> {
-    const queryBuilder = this.contractRepository.createQueryBuilder('contract').where({
-      ...(contractNumber ? { contractNumber: Like(`%${contractNumber}%`) } : null),
-      ...(title ? { title: Like(`%${title}%`) } : null),
-      ...(isNumber(type) ? { type } : null),
-      ...(isNumber(status) ? { status } : null)
-    });
+    const queryBuilder = this.contractRepository
+      .createQueryBuilder('contract')
+      .leftJoin('contract.files', 'files')
+      .addSelect(['files.id', 'files.path'])
+      .where({
+        ...(contractNumber ? { contractNumber: Like(`%${contractNumber}%`) } : null),
+        ...(title ? { title: Like(`%${title}%`) } : null),
+        ...(isNumber(type) ? { type } : null),
+        ...(isNumber(status) ? { status } : null)
+      });
 
     return paginate<ContractEntity>(queryBuilder, {
       page,
@@ -47,8 +57,30 @@ export class ContractService {
   /**
    * 更新
    */
-  async update(id: number, dto: Partial<ContractDto>): Promise<void> {
-    await this.contractRepository.update(id, dto);
+  async update(id: number, { fileIds, ...data }: Partial<ContractUpdateDto>): Promise<void> {
+    await this.entityManager.transaction(async manager => {
+      await manager.update(ContractEntity, id, {
+        ...data
+      });
+      const contract = await this.contractRepository
+        .createQueryBuilder('contract')
+        .leftJoinAndSelect('contract.files', 'files')
+        .where('contract.id = :id', { id })
+        .getOne();
+      const count = await this.storageRepository
+        .createQueryBuilder('storage')
+        .where('storage.id in(:fileIds)', { fileIds })
+        .getCount();
+      if (count !== fileIds?.length) {
+        throw new BusinessException(ErrorEnum.STORAGE_NOT_FOUND);
+      }
+      // 附件要批量更新
+      await manager
+        .createQueryBuilder()
+        .relation(ContractEntity, 'files')
+        .of(id)
+        .addAndRemove(fileIds, contract.files);
+    });
   }
 
   /**
@@ -70,4 +102,28 @@ export class ContractService {
       .getOne();
     return info;
   }
+
+  /**
+   * 解除附件关联
+   * @param id 合同ID
+   * @param fileIds 附件ID
+   */
+  async unlinkAttachments(id: number, fileIds: number[]) {
+    await this.entityManager.transaction(async manager => {
+      const contract = await this.contractRepository
+        .createQueryBuilder('contract')
+        .leftJoinAndSelect('contract.files', 'files')
+        .where('contract.id = :id', { id })
+        .getOne();
+      const linkedFiles = contract.files
+        .map(item => item.id)
+        .filter(item => !fileIds.includes(item));
+      // 附件要批量更新
+      await manager
+        .createQueryBuilder()
+        .relation(ContractEntity, 'files')
+        .of(id)
+        .addAndRemove(linkedFiles, contract.files);
+    });
+  }
 }
diff --git a/src/modules/tools/storage/storage.dto.ts b/src/modules/tools/storage/storage.dto.ts
index ed25a7e..1dfd010 100644
--- a/src/modules/tools/storage/storage.dto.ts
+++ b/src/modules/tools/storage/storage.dto.ts
@@ -1,4 +1,5 @@
 import { ApiProperty } from '@nestjs/swagger';
+import { Transform } from 'class-transformer';
 import { ArrayNotEmpty, IsArray, IsOptional, IsString } from 'class-validator';
 
 import { PagerDto } from '~/common/dto/pager.dto';
@@ -32,6 +33,18 @@ export class StoragePageDto extends PagerDto {
   @IsString()
   @IsOptional()
   username: string;
+
+  @ApiProperty({ description: '附件' })
+  @IsOptional()
+  @Transform(
+    ({ value: val }) => {
+      return val ? val.split(',').map(item => Number(item)) : [];
+    },
+    {
+      toClassOnly: true
+    }
+  )
+  ids: number[];
 }
 
 export class StorageCreateDto {
diff --git a/src/modules/tools/storage/storage.entity.ts b/src/modules/tools/storage/storage.entity.ts
index 7680f12..69253a5 100644
--- a/src/modules/tools/storage/storage.entity.ts
+++ b/src/modules/tools/storage/storage.entity.ts
@@ -1,7 +1,8 @@
-import { ApiProperty } from '@nestjs/swagger';
-import { Column, Entity } from 'typeorm';
+import { ApiHideProperty, ApiProperty } from '@nestjs/swagger';
+import { Column, Entity, ManyToMany, Relation } from 'typeorm';
 
 import { CommonEntity } from '~/common/entity/common.entity';
+import { ContractEntity } from '~/modules/contract/contract.entity';
 
 @Entity({ name: 'tool_storage' })
 export class Storage extends CommonEntity {
@@ -37,4 +38,8 @@ export class Storage extends CommonEntity {
   @Column({ nullable: true, name: 'user_id' })
   @ApiProperty({ description: '用户ID' })
   userId: number;
+
+  @ApiHideProperty()
+  @ManyToMany(() => ContractEntity, contract => contract.files)
+  contracts: Relation<ContractEntity[]>;
 }
diff --git a/src/modules/tools/storage/storage.service.ts b/src/modules/tools/storage/storage.service.ts
index 5a8cbf3..414af8f 100644
--- a/src/modules/tools/storage/storage.service.ts
+++ b/src/modules/tools/storage/storage.service.ts
@@ -1,6 +1,6 @@
 import { Injectable } from '@nestjs/common';
-import { InjectRepository } from '@nestjs/typeorm';
-import { Between, Like, Repository } from 'typeorm';
+import { InjectEntityManager, InjectRepository } from '@nestjs/typeorm';
+import { Between, EntityManager, In, Like, Repository } from 'typeorm';
 
 import { paginateRaw } from '~/helper/paginate';
 import { PaginationTypeEnum } from '~/helper/paginate/interface';
@@ -11,10 +11,13 @@ import { deleteFile } from '~/utils';
 
 import { StorageCreateDto, StoragePageDto } from './storage.dto';
 import { StorageInfo } from './storage.modal';
+import { BusinessException } from '~/common/exceptions/biz.exception';
+import { ErrorEnum } from '~/constants/error-code.constant';
 
 @Injectable()
 export class StorageService {
   constructor(
+    @InjectEntityManager() private entityManager: EntityManager,
     @InjectRepository(Storage)
     private storageRepository: Repository<Storage>,
     @InjectRepository(UserEntity)
@@ -32,11 +35,18 @@ export class StorageService {
    * 删除文件
    */
   async delete(fileIds: number[]): Promise<void> {
-    const items = await this.storageRepository.findByIds(fileIds);
-    await this.storageRepository.delete(fileIds);
-
-    items.forEach(el => {
-      deleteFile(el.path);
+    await this.entityManager.transaction(async manager => {
+      const items = await this.storageRepository.findBy({ id: In(fileIds) });
+      try {
+        await manager.delete(Storage, fileIds);
+        items.forEach(el => {
+          deleteFile(el.path);
+        });
+      } catch (e) {
+        if (e.code === 'ER_ROW_IS_REFERENCED_2') {
+          throw new BusinessException(ErrorEnum.STORAGE_REFRENCE_EXISTS);
+        }
+      }
     });
   }
 
@@ -48,7 +58,8 @@ export class StorageService {
     size,
     extName,
     time,
-    username
+    username,
+    ids
   }: StoragePageDto): Promise<Pagination<StorageInfo>> {
     const queryBuilder = this.storageRepository
       .createQueryBuilder('storage')
@@ -61,7 +72,8 @@ export class StorageService {
         ...(time && { createdAt: Between(time[0], time[1]) }),
         ...(username && {
           userId: await (await this.userRepository.findOneBy({ username })).id
-        })
+        }),
+        ...(ids && { id: In(ids) })
       })
       .orderBy('storage.created_at', 'DESC');
 
diff --git a/src/modules/tools/upload/upload.controller.ts b/src/modules/tools/upload/upload.controller.ts
index 7c44644..31756ab 100644
--- a/src/modules/tools/upload/upload.controller.ts
+++ b/src/modules/tools/upload/upload.controller.ts
@@ -38,10 +38,10 @@ export class UploadController {
     //   console.log(part.file)
 
     try {
-      const path = await this.uploadService.saveFile(file, user.uid);
+      const savedFile = await this.uploadService.saveFile(file, user.uid);
 
       return {
-        filename: path
+        filename: savedFile
       };
     } catch (error) {
       console.log(error);
diff --git a/src/modules/tools/upload/upload.service.ts b/src/modules/tools/upload/upload.service.ts
index 605f977..05b2a31 100644
--- a/src/modules/tools/upload/upload.service.ts
+++ b/src/modules/tools/upload/upload.service.ts
@@ -25,7 +25,7 @@ export class UploadService {
   /**
    * 保存文件上传记录
    */
-  async saveFile(file: MultipartFile, userId: number): Promise<string> {
+  async saveFile(file: MultipartFile, userId: number): Promise<{ id: number; path: string }> {
     if (isNil(file)) throw new NotFoundException('Have not any file to upload!');
 
     const fileName = file.filename;
@@ -37,7 +37,7 @@ export class UploadService {
 
     saveLocalFile(await file.toBuffer(), name);
 
-    await this.storageRepository.save({
+    const storage = await this.storageRepository.save({
       name,
       fileName,
       extName,
@@ -47,6 +47,6 @@ export class UploadService {
       userId
     });
 
-    return path;
+    return { path, id: storage.id };
   }
 }