diff --git a/apps/backend/src/app.module.ts b/apps/backend/src/app.module.ts
index 112cfd0..b8c3741 100644
--- a/apps/backend/src/app.module.ts
+++ b/apps/backend/src/app.module.ts
@@ -12,6 +12,7 @@ import { BlogModule } from './blog/blog.module';
 import { AdminModule } from './admin/admin.module';
 import { OssModule } from './oss/oss.module';
 import { ThrottlerModule } from '@nestjs/throttler';
+import { CaptchaModule } from './captcha/captcha.module';
 
 @Module({
   imports: [
@@ -43,6 +44,7 @@ import { ThrottlerModule } from '@nestjs/throttler';
     BlogModule,
     AdminModule,
     OssModule,
+    CaptchaModule,
   ],
   controllers: [AppController],
   providers: [AppService],
diff --git a/apps/backend/src/captcha/captcha.controller.spec.ts b/apps/backend/src/captcha/captcha.controller.spec.ts
new file mode 100644
index 0000000..a257614
--- /dev/null
+++ b/apps/backend/src/captcha/captcha.controller.spec.ts
@@ -0,0 +1,18 @@
+import { Test, TestingModule } from '@nestjs/testing';
+import { CaptchaController } from './captcha.controller';
+
+describe('CaptchaController', () => {
+  let controller: CaptchaController;
+
+  beforeEach(async () => {
+    const module: TestingModule = await Test.createTestingModule({
+      controllers: [CaptchaController],
+    }).compile();
+
+    controller = module.get<CaptchaController>(CaptchaController);
+  });
+
+  it('should be defined', () => {
+    expect(controller).toBeDefined();
+  });
+});
diff --git a/apps/backend/src/captcha/captcha.controller.ts b/apps/backend/src/captcha/captcha.controller.ts
new file mode 100644
index 0000000..e5f9259
--- /dev/null
+++ b/apps/backend/src/captcha/captcha.controller.ts
@@ -0,0 +1,10 @@
+import { Controller, Get } from '@nestjs/common';
+import { GetCaptchaDto } from './dto/get-captcha.dto';
+
+@Controller('captcha')
+export class CaptchaController {
+    @Get()
+    async getCaptcha(dto: GetCaptchaDto) {
+        
+    }
+}
diff --git a/apps/backend/src/captcha/captcha.module.ts b/apps/backend/src/captcha/captcha.module.ts
new file mode 100644
index 0000000..4b34c4f
--- /dev/null
+++ b/apps/backend/src/captcha/captcha.module.ts
@@ -0,0 +1,11 @@
+import { Module } from '@nestjs/common';
+import { CaptchaService } from './captcha.service';
+import { CaptchaController } from './captcha.controller';
+import { CaptchaRateLimitService } from './service/rate-limit';
+
+@Module({
+  providers: [CaptchaService, CaptchaRateLimitService],
+  controllers: [CaptchaController],
+  imports: [],
+})
+export class CaptchaModule { }
diff --git a/apps/backend/src/captcha/captcha.service.spec.ts b/apps/backend/src/captcha/captcha.service.spec.ts
new file mode 100644
index 0000000..82393cc
--- /dev/null
+++ b/apps/backend/src/captcha/captcha.service.spec.ts
@@ -0,0 +1,18 @@
+import { Test, TestingModule } from '@nestjs/testing';
+import { CaptchaService } from './captcha.service';
+
+describe('CaptchaService', () => {
+  let service: CaptchaService;
+
+  beforeEach(async () => {
+    const module: TestingModule = await Test.createTestingModule({
+      providers: [CaptchaService],
+    }).compile();
+
+    service = module.get<CaptchaService>(CaptchaService);
+  });
+
+  it('should be defined', () => {
+    expect(service).toBeDefined();
+  });
+});
diff --git a/apps/backend/src/captcha/captcha.service.ts b/apps/backend/src/captcha/captcha.service.ts
new file mode 100644
index 0000000..d5d7f8b
--- /dev/null
+++ b/apps/backend/src/captcha/captcha.service.ts
@@ -0,0 +1,27 @@
+import { Injectable } from '@nestjs/common';
+import { ErrorCode } from 'src/common/constants/error-codes';
+import { BusinessException } from 'src/common/exceptions/business.exception';
+
+export enum CaptchaContext {
+    SEND_SMS = 'send_sms',
+    PASSKEY = 'passkey',
+}
+
+@Injectable()
+export class CaptchaService {
+    public async generate(context: CaptchaContext, ip: string, userId?: string) {
+        await this.checkRateLimit(ip, context)
+    }
+
+    public async verify(token: string, ip: string, userId?: string) {
+
+    }
+
+    private async checkRateLimit(ip: string, context: CaptchaContext) {
+        /** @todo */
+        throw new BusinessException({
+            code: ErrorCode.CAPTCHA_RARE_LIMIT,
+            message: '服务器处理不过来了，过会儿再试试吧',
+        });
+    }
+}
diff --git a/apps/backend/src/captcha/dto/get-captcha.dto.ts b/apps/backend/src/captcha/dto/get-captcha.dto.ts
new file mode 100644
index 0000000..edb62f6
--- /dev/null
+++ b/apps/backend/src/captcha/dto/get-captcha.dto.ts
@@ -0,0 +1,16 @@
+import { IsEnum, IsOptional, IsUUID } from "class-validator";
+
+export enum CaptchaContext {
+    SEND_SMS = 'send_sms',
+    PASSKEY = 'passkey',
+}
+
+export class GetCaptchaDto {
+
+    @IsEnum(CaptchaContext, { message: '无效的context' })
+    context: string;
+
+    @IsOptional()
+    @IsUUID('4', { message: 'userId不合法' })
+    userId?: string;
+}
\ No newline at end of file
diff --git a/apps/backend/src/captcha/service/rate-limit.ts b/apps/backend/src/captcha/service/rate-limit.ts
new file mode 100644
index 0000000..cab5348
--- /dev/null
+++ b/apps/backend/src/captcha/service/rate-limit.ts
@@ -0,0 +1,3 @@
+export class CaptchaRateLimitService {
+
+}
\ No newline at end of file
diff --git a/apps/backend/src/common/constants/error-codes.ts b/apps/backend/src/common/constants/error-codes.ts
index c307109..b7affd8 100644
--- a/apps/backend/src/common/constants/error-codes.ts
+++ b/apps/backend/src/common/constants/error-codes.ts
@@ -29,8 +29,7 @@ export const ErrorCode = {
     BLOG_PERMISSION_DENIED: -3002,
 
     // 验证模块（4000 ~ 4999）
-    VERIFICATION_CODE_EXPIRED: -4001,
-    VERIFICATION_CODE_INCORRECT: -4002,
+    CAPTCHA_RARE_LIMIT: -4001,
 
     // 通知模块（5000 ~ 5999）
     NOTIFICATION_SEND_FAILED: -5001,