diff --git a/.github/workflows/deploy.yml b/.github/workflows/deploy.yml
index fd7a9a4..120b462 100644
--- a/.github/workflows/deploy.yml
+++ b/.github/workflows/deploy.yml
@@ -25,6 +25,11 @@ jobs:
           username: ${{ secrets.DOCKER_USERNAME }}
           password: ${{ secrets.DOCKERHUB_TOKEN }}
 
+      # Docker Buildx 설정 추가
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+
       # Dockerfile을 사용하여 이미지를 빌드하고 Docker Hub에 푸시합니다.
       - name: Build and push Docker image
         uses: docker/build-push-action@v6.16.0
diff --git a/src/main/java/com/teamEWSN/gitdeun/mindmap/service/MindmapSseService.java b/src/main/java/com/teamEWSN/gitdeun/mindmap/service/MindmapSseService.java
index f52dd44..fdcad7a 100644
--- a/src/main/java/com/teamEWSN/gitdeun/mindmap/service/MindmapSseService.java
+++ b/src/main/java/com/teamEWSN/gitdeun/mindmap/service/MindmapSseService.java
@@ -45,19 +45,26 @@ public SseEmitter createConnection(Long mapId, CustomUserDetails userDetails) {
 
         connectionsByMapId.computeIfAbsent(mapId, k -> new CopyOnWriteArrayList<>()).add(connection);
 
-
         // 연결 종료 시 정리 (기존 로직 개선)
-        emitter.onCompletion(() -> removeConnection(mapId, connection));
-        emitter.onTimeout(() -> removeConnection(mapId, connection));
+        emitter.onCompletion(() -> {
+            removeConnection(mapId, connection);
+            broadcastUserListUpdate(mapId);
+        });
+        emitter.onTimeout(() -> {
+            removeConnection(mapId, connection);
+            broadcastUserListUpdate(mapId);
+        });
         emitter.onError(throwable -> {
             log.error("SSE 연결 오류 - 마인드맵 ID: {}, 사용자 ID: {}", mapId, userDetails.getId(), throwable);
             removeConnection(mapId, connection);
+            broadcastUserListUpdate(mapId);
         });
 
         // 연결 확인용 초기 메시지
         sendToEmitter(emitter, "마인드맵 " + mapId + " 실시간 연결 성공");
-
         log.info("SSE 연결 생성 - 마인드맵 ID: {}, 사용자 ID: {}", mapId, userDetails.getId());
+
+        broadcastUserListUpdate(mapId);
         return emitter;
     }
 
@@ -158,9 +165,17 @@ private void removeConnection(Long mapId, SseConnection connection) {
                 connectionsByMapId.remove(mapId);
                 log.info("마인드맵 ID {} 의 모든 구독자 연결 종료", mapId);
             }
+            broadcastUserListUpdate(mapId);
         }
     }
 
+    // 사용자 목록 변경을 모든 클라이언트에게 브로드캐스트
+    public void broadcastUserListUpdate(Long mapId) {
+        // 현재 접속자 목록
+        List<ConnectedUserDto> connectedUsers = getConnectedUsers(mapId);
+        // "user-list-updated" 라는 이벤트 이름으로 현재 접속자 목록을 전송
+        sendToMapSubscribers(mapId, "user-list-updated", connectedUsers);
+    }
 
     // 접속된 사용자 수 조회
     public int getConnectionCount(Long mapId) {
diff --git a/src/main/java/com/teamEWSN/gitdeun/notification/controller/NotificationController.java b/src/main/java/com/teamEWSN/gitdeun/notification/controller/NotificationController.java
index a122231..2093d46 100644
--- a/src/main/java/com/teamEWSN/gitdeun/notification/controller/NotificationController.java
+++ b/src/main/java/com/teamEWSN/gitdeun/notification/controller/NotificationController.java
@@ -46,6 +46,14 @@ public ResponseEntity<Void> markNotificationAsRead(
         return ResponseEntity.noContent().build();
     }
 
+    // 모든 알림 읽음 처리
+    @PatchMapping("/read-all")
+    public ResponseEntity<Void> markAllNotificationsAsRead(
+        @AuthenticationPrincipal CustomUserDetails userDetails) {
+        notificationService.markAllAsRead(userDetails.getId());
+        return ResponseEntity.noContent().build();
+    }
+
     // 알림 삭제
     @DeleteMapping("/{notificationId}")
     public ResponseEntity<Void> deleteNotification(
diff --git a/src/main/java/com/teamEWSN/gitdeun/notification/repository/NotificationRepository.java b/src/main/java/com/teamEWSN/gitdeun/notification/repository/NotificationRepository.java
index bfd820f..823cd9e 100644
--- a/src/main/java/com/teamEWSN/gitdeun/notification/repository/NotificationRepository.java
+++ b/src/main/java/com/teamEWSN/gitdeun/notification/repository/NotificationRepository.java
@@ -5,6 +5,9 @@
 import org.springframework.data.domain.Page;
 import org.springframework.data.domain.Pageable;
 import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Modifying;
+import org.springframework.data.jpa.repository.Query;
+import org.springframework.data.repository.query.Param;
 import org.springframework.stereotype.Repository;
 
 import java.util.Optional;
@@ -20,4 +23,9 @@ public interface NotificationRepository extends JpaRepository<Notification, Long
 
     // 특정 알림이 해당 사용자의 소유인지 확인하며 조회
     Optional<Notification> findByIdAndUser(Long id, User user);
+
+    // 특정 사용자의 모든 읽지 않은 알림을 읽음으로 처리하는 메서드
+    @Modifying
+    @Query("UPDATE Notification n SET n.read = true WHERE n.user = :user AND n.read = false")
+    void markAllAsReadByUser(@Param("user") User user);
 }
\ No newline at end of file
diff --git a/src/main/java/com/teamEWSN/gitdeun/notification/service/NotificationService.java b/src/main/java/com/teamEWSN/gitdeun/notification/service/NotificationService.java
index c430aa2..777e6c6 100644
--- a/src/main/java/com/teamEWSN/gitdeun/notification/service/NotificationService.java
+++ b/src/main/java/com/teamEWSN/gitdeun/notification/service/NotificationService.java
@@ -240,6 +240,18 @@ public void markAsRead(Long notificationId, Long userId) {
         }
     }
 
+    /**
+     * 사용자의 모든 알림을 읽음으로 처리
+     */
+    @Transactional
+    public void markAllAsRead(Long userId) {
+        User user = getUserById(userId);
+        notificationRepository.markAllAsReadByUser(user);
+
+        // 변경된 '읽지 않은 알림 개수'(0)를 실시간으로 전송
+        notificationSseService.sendUnreadCount(user.getId(), 0);
+    }
+
     /**
      * 알림 삭제
      */