diff --git a/app/Services/DepartmentPermissionService.php b/app/Services/DepartmentPermissionService.php
index 6eb69983..45973e45 100644
--- a/app/Services/DepartmentPermissionService.php
+++ b/app/Services/DepartmentPermissionService.php
@@ -350,34 +350,30 @@ public function allowAllPermissions(int $departmentId, ?int $tenantId = null, st
      */
     public function denyAllPermissions(int $departmentId, ?int $tenantId = null, string $guardName = 'api'): void
     {
-        $query = Menu::where('is_active', 1);
+        // menu: 접두사를 가진 해당 가드의 모든 권한 ID 조회
+        $query = DB::table('permissions')
+            ->where('guard_name', $guardName)
+            ->where('name', 'like', 'menu:%');
+
         if ($tenantId) {
             $query->where('tenant_id', $tenantId);
         }
-        $menus = $query->get();
 
-        foreach ($menus as $menu) {
-            foreach ($this->permissionTypes as $type) {
-                $permissionName = "menu:{$menu->id}.{$type}";
-                $permission = Permission::where('name', $permissionName)
-                    ->where('guard_name', $guardName)
-                    ->first();
+        $permissionIds = $query->pluck('id');
 
-                if ($permission) {
-                    // Soft delete all ALLOW overrides for this department
-                    DB::table('permission_overrides')
-                        ->where('model_type', Department::class)
-                        ->where('model_id', $departmentId)
-                        ->where('permission_id', $permission->id)
-                        ->where('tenant_id', $tenantId)
-                        ->where('effect', 1)
-                        ->whereNull('deleted_at')
-                        ->update([
-                            'deleted_at' => now(),
-                            'deleted_by' => auth()->id(),
-                        ]);
-                }
-            }
+        if ($permissionIds->isNotEmpty()) {
+            // Soft delete all ALLOW overrides for this department
+            DB::table('permission_overrides')
+                ->where('model_type', Department::class)
+                ->where('model_id', $departmentId)
+                ->whereIn('permission_id', $permissionIds)
+                ->where('tenant_id', $tenantId)
+                ->where('effect', 1)
+                ->whereNull('deleted_at')
+                ->update([
+                    'deleted_at' => now(),
+                    'deleted_by' => auth()->id(),
+                ]);
         }
     }
 
diff --git a/resources/views/department-permissions/index.blade.php b/resources/views/department-permissions/index.blade.php
index 434f5489..e8237c14 100644
--- a/resources/views/department-permissions/index.blade.php
+++ b/resources/views/department-permissions/index.blade.php
@@ -53,7 +53,7 @@ class="department-button px-4 py-2 text-sm font-medium rounded-lg border transit
 
                     <button
                         type="button"
-                        class="px-4 py-2 bg-green-600 text-white text-sm font-medium rounded-lg hover:bg-green-700 focus:outline-none focus:ring-2 focus:ring-green-500"
+                        class="bulk-action-btn px-4 py-2 bg-green-600 text-white text-sm font-medium rounded-lg hover:bg-green-700 focus:outline-none focus:ring-2 focus:ring-green-500"
                         hx-post="/api/admin/department-permissions/allow-all"
                         hx-target="#permission-matrix"
                         hx-include="[name='department_id'],[name='guard_name']"
@@ -62,20 +62,11 @@ class="px-4 py-2 bg-green-600 text-white text-sm font-medium rounded-lg hover:bg
                     </button>
                     <button
                         type="button"
-                        class="px-4 py-2 bg-red-600 text-white text-sm font-medium rounded-lg hover:bg-red-700 focus:outline-none focus:ring-2 focus:ring-red-500"
+                        class="bulk-action-btn px-4 py-2 bg-gray-500 text-white text-sm font-medium rounded-lg hover:bg-gray-600 focus:outline-none focus:ring-2 focus:ring-gray-400"
                         hx-post="/api/admin/department-permissions/deny-all"
                         hx-target="#permission-matrix"
                         hx-include="[name='department_id'],[name='guard_name']"
-                    >
-                        전체 거부
-                    </button>
-                    <button
-                        type="button"
-                        class="px-4 py-2 bg-gray-500 text-white text-sm font-medium rounded-lg hover:bg-gray-600 focus:outline-none focus:ring-2 focus:ring-gray-400"
-                        hx-post="/api/admin/department-permissions/reset"
-                        hx-target="#permission-matrix"
-                        hx-include="[name='department_id'],[name='guard_name']"
-                        title="모든 메뉴의 조회(view) 권한만 허용"
+                        title="모든 권한 체크 해제"
                     >
                         초기화
                     </button>
@@ -85,10 +76,21 @@ class="px-4 py-2 bg-gray-500 text-white text-sm font-medium rounded-lg hover:bg-
     </div>
 
     <!-- 권한 매트릭스 테이블 -->
-    <div id="permission-matrix" class="bg-white rounded-lg shadow-sm">
+    <div id="permission-matrix" class="bg-white rounded-lg shadow-sm relative">
         @include('department-permissions.partials.empty-state')
     </div>
 
+    <!-- 로딩 오버레이 -->
+    <div id="permission-loading" class="hidden fixed inset-0 z-50 flex items-center justify-center bg-black/30">
+        <div class="bg-white rounded-xl shadow-lg px-8 py-6 flex items-center gap-4">
+            <svg class="animate-spin h-6 w-6 text-blue-600" xmlns="http://www.w3.org/2000/svg" fill="none" viewBox="0 0 24 24">
+                <circle class="opacity-25" cx="12" cy="12" r="10" stroke="currentColor" stroke-width="4"></circle>
+                <path class="opacity-75" fill="currentColor" d="M4 12a8 8 0 018-8V0C5.373 0 0 5.373 0 12h4zm2 5.291A7.962 7.962 0 014 12H0c0 3.042 1.135 5.824 3 7.938l3-2.647z"></path>
+            </svg>
+            <span class="text-gray-700 font-medium text-sm">권한을 변경하고 있습니다...</span>
+        </div>
+    </div>
+
 <script>
     function selectDepartment(button) {
         // 모든 버튼의 활성 상태 제거
@@ -114,6 +116,18 @@ function selectDepartment(button) {
         document.getElementById('action-buttons').style.display = 'block';
     }
 
+    // 벌크 액션 버튼 로딩 오버레이
+    document.addEventListener('htmx:beforeRequest', function(e) {
+        if (e.detail.elt.classList.contains('bulk-action-btn')) {
+            document.getElementById('permission-loading').classList.remove('hidden');
+        }
+    });
+    document.addEventListener('htmx:afterRequest', function(e) {
+        if (e.detail.elt.classList.contains('bulk-action-btn')) {
+            document.getElementById('permission-loading').classList.add('hidden');
+        }
+    });
+
     // 페이지 로드 시 첫 번째 부서 자동 선택 (특정 테넌트 선택 시에만)
     document.addEventListener('DOMContentLoaded', function() {
         const autoSelectButton = document.querySelector('.department-button[data-auto-select="true"]');