diff --git a/lab-27/lab-27-webflux-mongodb/pom.xml b/lab-27/lab-27-webflux-mongodb/pom.xml
new file mode 100644
index 00000000..5631759c
--- /dev/null
+++ b/lab-27/lab-27-webflux-mongodb/pom.xml
@@ -0,0 +1,38 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <parent>
+        <groupId>org.springframework.boot</groupId>
+        <artifactId>spring-boot-starter-parent</artifactId>
+        <version>2.2.1.RELEASE</version>
+        <relativePath/> <!-- lookup parent from repository -->
+    </parent>
+    <modelVersion>4.0.0</modelVersion>
+
+    <artifactId>lab-27-webflux-mongodb</artifactId>
+
+    <dependencies>
+        <!-- 实现对 Spring WebFlux 的自动化配置 -->
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-webflux</artifactId>
+            <version>2.2.1.RELEASE</version>
+        </dependency>
+
+        <!-- 自动化配置响应式的 Spring Data Mongodb -->
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-data-mongodb-reactive</artifactId>
+        </dependency>
+
+        <!-- 方便等会写单元测试 -->
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-test</artifactId>
+            <scope>test</scope>
+        </dependency>
+
+    </dependencies>
+
+</project>
diff --git a/lab-27/lab-27-webflux-mongodb/src/main/java/cn/iocoder/springboot/lab27/springwebflux/Application.java b/lab-27/lab-27-webflux-mongodb/src/main/java/cn/iocoder/springboot/lab27/springwebflux/Application.java
new file mode 100644
index 00000000..4f207dfc
--- /dev/null
+++ b/lab-27/lab-27-webflux-mongodb/src/main/java/cn/iocoder/springboot/lab27/springwebflux/Application.java
@@ -0,0 +1,13 @@
+package cn.iocoder.springboot.lab27.springwebflux;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class Application {
+
+    public static void main(String[] args) {
+        SpringApplication.run(Application.class, args);
+    }
+
+}
diff --git a/lab-27/lab-27-webflux-mongodb/src/main/java/cn/iocoder/springboot/lab27/springwebflux/controller/UserController.java b/lab-27/lab-27-webflux-mongodb/src/main/java/cn/iocoder/springboot/lab27/springwebflux/controller/UserController.java
new file mode 100644
index 00000000..e1307faa
--- /dev/null
+++ b/lab-27/lab-27-webflux-mongodb/src/main/java/cn/iocoder/springboot/lab27/springwebflux/controller/UserController.java
@@ -0,0 +1,154 @@
+package cn.iocoder.springboot.lab27.springwebflux.controller;
+
+import cn.iocoder.springboot.lab27.springwebflux.dao.UserRepository;
+import cn.iocoder.springboot.lab27.springwebflux.dataobject.UserDO;
+import cn.iocoder.springboot.lab27.springwebflux.dto.UserAddDTO;
+import cn.iocoder.springboot.lab27.springwebflux.dto.UserUpdateDTO;
+import cn.iocoder.springboot.lab27.springwebflux.vo.UserVO;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.web.bind.annotation.*;
+import reactor.core.publisher.Flux;
+import reactor.core.publisher.Mono;
+
+import java.util.Date;
+import java.util.Objects;
+import java.util.function.Function;
+
+/**
+ * 用户 Controller
+ */
+@RestController
+@RequestMapping("/users")
+public class UserController {
+
+    @Autowired
+    private UserRepository userRepository;
+
+    /**
+     * 查询用户列表
+     *
+     * @return 用户列表
+     */
+    @GetMapping("/list")
+    public Flux<UserVO> list() {
+        // 返回列表
+        return userRepository.findAll()
+                .map(userDO -> new UserVO().setId(userDO.getId()).setUsername(userDO.getUsername()));
+    }
+
+    /**
+     * 获得指定用户编号的用户
+     *
+     * @param id 用户编号
+     * @return 用户
+     */
+    @GetMapping("/get")
+    public Mono<UserVO> get(@RequestParam("id") Integer id) {
+        // 返回
+        return userRepository.findById(id)
+                .map(userDO -> new UserVO().setId(userDO.getId()).setUsername(userDO.getUsername()));
+    }
+
+    /**
+     * 添加用户
+     *
+     * @param addDTO 添加用户信息 DTO
+     * @return 添加成功的用户编号
+     */
+    @PostMapping("add")
+    public Mono<Integer> add(UserAddDTO addDTO) {
+        // 查询用户
+        Mono<UserDO> user = userRepository.findByUsername(addDTO.getUsername());
+
+        // 执行插入
+        return user.flatMap(new Function<UserDO, Mono<? extends Integer>>() {
+
+            @Override
+            public Mono<? extends Integer> apply(UserDO userDO) {
+                if (userDO != null) {
+                    // 返回 -1 表示插入失败。
+                    // 实际上，一般是抛出 ServiceException 异常。因为这个示例项目里暂时没做全局异常的定义，所以暂时返回 -1 啦
+                    return Mono.just(-1);
+                }
+                // 将 addDTO 转成 UserDO
+                userDO = new UserDO().setId((int) (System.currentTimeMillis() / 1000)) // 使用当前时间戳的描述，作为 ID 。
+                        .setUsername(addDTO.getUsername())
+                        .setPassword(addDTO.getPassword())
+                        .setCreateTime(new Date());
+                // 插入数据库
+                return userRepository.save(userDO).map(UserDO::getId);
+            }
+
+        });
+    }
+
+    /**
+     * 更新指定用户编号的用户
+     *
+     * @param updateDTO 更新用户信息 DTO
+     * @return 是否修改成功
+     */
+    @PostMapping("/update")
+    public Mono<Boolean> update(UserUpdateDTO updateDTO) {
+        // 查询用户
+        Mono<UserDO> user = userRepository.findById(updateDTO.getId());
+
+        // 执行更新
+        return user.flatMap(new Function<UserDO, Mono<Boolean>>() {
+
+            @Override
+            public Mono<Boolean> apply(UserDO userDO) {
+                // 如果不存在该用户，则直接返回 false 失败
+                if (userDO == null) {
+                    return Mono.just(false);
+                }
+                // 查询用户是否存在
+                return userRepository.findByUsername(updateDTO.getUsername())
+                        .flatMap(new Function<UserDO, Mono<? extends Boolean>>() {
+
+                            @Override
+                            public Mono<? extends Boolean> apply(UserDO usernameUserDO) {
+                                // 如果用户名已经使用
+                                if (usernameUserDO != null && !Objects.equals(updateDTO.getId(), usernameUserDO.getId())) {
+                                    return Mono.just(false);
+                                }
+                                // 执行更新
+                                userDO.setUsername(updateDTO.getUsername());
+                                userDO.setPassword(updateDTO.getPassword());
+                                return userRepository.save(userDO).map(userDO -> true); // 返回 true 成功
+                            }
+
+                        });
+            }
+
+        });
+    }
+
+    /**
+     * 删除指定用户编号的用户
+     *
+     * @param id 用户编号
+     * @return 是否删除成功
+     */
+    @PostMapping("/delete") // URL 修改成 /delete ，RequestMethod 改成 DELETE
+    public Mono<Boolean> delete(@RequestParam("id") Integer id) {
+        // 查询用户
+        Mono<UserDO> user = userRepository.findById(id);
+
+        // 执行删除。这里仅仅是示例，项目中不要物理删除，而是标记删除
+        return user.flatMap(new Function<UserDO, Mono<? extends Boolean>>() {
+
+            @Override
+            public Mono<? extends Boolean> apply(UserDO userDO) {
+                // 如果不存在该用户，则直接返回 false 失败
+                if (userDO == null) {
+                    return Mono.just(false);
+                }
+                // 执行删除
+                return userRepository.deleteById(id).map(aVoid -> true); // 返回 true 成功
+            }
+
+        });
+    }
+
+}
diff --git a/lab-27/lab-27-webflux-mongodb/src/main/java/cn/iocoder/springboot/lab27/springwebflux/dao/UserRepository.java b/lab-27/lab-27-webflux-mongodb/src/main/java/cn/iocoder/springboot/lab27/springwebflux/dao/UserRepository.java
new file mode 100644
index 00000000..9ee61f79
--- /dev/null
+++ b/lab-27/lab-27-webflux-mongodb/src/main/java/cn/iocoder/springboot/lab27/springwebflux/dao/UserRepository.java
@@ -0,0 +1,11 @@
+package cn.iocoder.springboot.lab27.springwebflux.dao;
+
+import cn.iocoder.springboot.lab27.springwebflux.dataobject.UserDO;
+import org.springframework.data.mongodb.repository.ReactiveMongoRepository;
+import reactor.core.publisher.Mono;
+
+public interface UserRepository extends ReactiveMongoRepository<UserDO, Integer> {
+
+    Mono<UserDO> findByUsername(String username);
+
+}
diff --git a/lab-27/lab-27-webflux-mongodb/src/main/java/cn/iocoder/springboot/lab27/springwebflux/dataobject/UserDO.java b/lab-27/lab-27-webflux-mongodb/src/main/java/cn/iocoder/springboot/lab27/springwebflux/dataobject/UserDO.java
new file mode 100644
index 00000000..6402c7f5
--- /dev/null
+++ b/lab-27/lab-27-webflux-mongodb/src/main/java/cn/iocoder/springboot/lab27/springwebflux/dataobject/UserDO.java
@@ -0,0 +1,75 @@
+package cn.iocoder.springboot.lab27.springwebflux.dataobject;
+
+import org.springframework.data.annotation.Id;
+import org.springframework.data.mongodb.core.mapping.Document;
+
+import java.util.Date;
+
+/**
+ * 用户 DO
+ */
+@Document(collection = "User")
+public class UserDO {
+
+    @Id
+    private Integer id;
+    /**
+     * 账号
+     */
+    private String username;
+    /**
+     * 密码
+     */
+    private String password;
+    /**
+     * 创建时间
+     */
+    private Date createTime;
+
+    public Integer getId() {
+        return id;
+    }
+
+    public UserDO setId(Integer id) {
+        this.id = id;
+        return this;
+    }
+
+    public String getUsername() {
+        return username;
+    }
+
+    public UserDO setUsername(String username) {
+        this.username = username;
+        return this;
+    }
+
+    public String getPassword() {
+        return password;
+    }
+
+    public UserDO setPassword(String password) {
+        this.password = password;
+        return this;
+    }
+
+    public Date getCreateTime() {
+        return createTime;
+    }
+
+    public UserDO setCreateTime(Date createTime) {
+        this.createTime = createTime;
+        return this;
+    }
+
+    @Override
+    public String toString() {
+        return "UserDO{" +
+                "id=" + id +
+                ", username='" + username + '\'' +
+                ", password='" + password + '\'' +
+                ", createTime=" + createTime +
+                '}';
+    }
+
+}
diff --git a/lab-27/lab-27-webflux-mongodb/src/main/java/cn/iocoder/springboot/lab27/springwebflux/dto/UserAddDTO.java b/lab-27/lab-27-webflux-mongodb/src/main/java/cn/iocoder/springboot/lab27/springwebflux/dto/UserAddDTO.java
new file mode 100644
index 00000000..32674a82
--- /dev/null
+++ b/lab-27/lab-27-webflux-mongodb/src/main/java/cn/iocoder/springboot/lab27/springwebflux/dto/UserAddDTO.java
@@ -0,0 +1,35 @@
+package cn.iocoder.springboot.lab27.springwebflux.dto;
+
+/**
+ * 用户添加 DTO
+ */
+public class UserAddDTO {
+
+    /**
+     * 账号
+     */
+    private String username;
+    /**
+     * 密码
+     */
+    private String password;
+
+    public String getUsername() {
+        return username;
+    }
+
+    public UserAddDTO setUsername(String username) {
+        this.username = username;
+        return this;
+    }
+
+    public String getPassword() {
+        return password;
+    }
+
+    public UserAddDTO setPassword(String password) {
+        this.password = password;
+        return this;
+    }
+
+}
diff --git a/lab-27/lab-27-webflux-mongodb/src/main/java/cn/iocoder/springboot/lab27/springwebflux/dto/UserUpdateDTO.java b/lab-27/lab-27-webflux-mongodb/src/main/java/cn/iocoder/springboot/lab27/springwebflux/dto/UserUpdateDTO.java
new file mode 100644
index 00000000..b02edb31
--- /dev/null
+++ b/lab-27/lab-27-webflux-mongodb/src/main/java/cn/iocoder/springboot/lab27/springwebflux/dto/UserUpdateDTO.java
@@ -0,0 +1,45 @@
+package cn.iocoder.springboot.lab27.springwebflux.dto;
+
+public class UserUpdateDTO {
+
+    /**
+     * 编号
+     */
+    private Integer id;
+    /**
+     * 账号
+     */
+    private String username;
+    /**
+     * 密码
+     */
+    private String password;
+
+    public Integer getId() {
+        return id;
+    }
+
+    public UserUpdateDTO setId(Integer id) {
+        this.id = id;
+        return this;
+    }
+
+    public String getUsername() {
+        return username;
+    }
+
+    public UserUpdateDTO setUsername(String username) {
+        this.username = username;
+        return this;
+    }
+
+    public String getPassword() {
+        return password;
+    }
+
+    public UserUpdateDTO setPassword(String password) {
+        this.password = password;
+        return this;
+    }
+
+}
diff --git a/lab-27/lab-27-webflux-mongodb/src/main/java/cn/iocoder/springboot/lab27/springwebflux/service/UserService.java b/lab-27/lab-27-webflux-mongodb/src/main/java/cn/iocoder/springboot/lab27/springwebflux/service/UserService.java
new file mode 100644
index 00000000..00332350
--- /dev/null
+++ b/lab-27/lab-27-webflux-mongodb/src/main/java/cn/iocoder/springboot/lab27/springwebflux/service/UserService.java
@@ -0,0 +1,13 @@
+package cn.iocoder.springboot.lab27.springwebflux.service;
+
+import cn.iocoder.springboot.lab27.springwebflux.vo.UserVO;
+import org.springframework.stereotype.Service;
+
+@Service
+public class UserService {
+
+    public UserVO get(Integer id) {
+        return new UserVO().setId(id).setUsername("test");
+    }
+
+}
diff --git a/lab-27/lab-27-webflux-mongodb/src/main/java/cn/iocoder/springboot/lab27/springwebflux/vo/UserVO.java b/lab-27/lab-27-webflux-mongodb/src/main/java/cn/iocoder/springboot/lab27/springwebflux/vo/UserVO.java
new file mode 100644
index 00000000..7dd64075
--- /dev/null
+++ b/lab-27/lab-27-webflux-mongodb/src/main/java/cn/iocoder/springboot/lab27/springwebflux/vo/UserVO.java
@@ -0,0 +1,35 @@
+package cn.iocoder.springboot.lab27.springwebflux.vo;
+
+/**
+ * 用户 VO
+ */
+public class UserVO {
+
+    /**
+     * 编号
+     */
+    private Integer id;
+    /**
+     * 账号
+     */
+    private String username;
+
+    public Integer getId() {
+        return id;
+    }
+
+    public UserVO setId(Integer id) {
+        this.id = id;
+        return this;
+    }
+
+    public String getUsername() {
+        return username;
+    }
+
+    public UserVO setUsername(String username) {
+        this.username = username;
+        return this;
+    }
+
+}
diff --git a/lab-27/lab-27-webflux-mongodb/src/main/resources/application.yaml b/lab-27/lab-27-webflux-mongodb/src/main/resources/application.yaml
new file mode 100644
index 00000000..9d5d76f0
--- /dev/null
+++ b/lab-27/lab-27-webflux-mongodb/src/main/resources/application.yaml
@@ -0,0 +1,18 @@
+spring:
+  data:
+    # MongoDB 配置项，对应 MongoProperties 类
+    mongodb:
+      host: 127.0.0.1
+      port: 27017
+      database: yourdatabase
+      username: test01
+      password: password01
+      # 上述属性，也可以只配置 uri
+
+logging:
+  level:
+    org:
+      springframework:
+        data:
+          mongodb:
+            core: DEBUG # 打印 mongodb 操作的具体语句。生产环境下，不建议开启。
diff --git a/lab-27/pom.xml b/lab-27/pom.xml
index d9dc6611..74c498ec 100644
--- a/lab-27/pom.xml
+++ b/lab-27/pom.xml
@@ -15,6 +15,7 @@
         <module>lab-27-webflux-01</module>
         <module>lab-27-webflux-02</module>
         <module>lab-27-webflux-03</module>
+        <module>lab-27-webflux-mongodb</module>
     </modules>