diff --git a/backend/src/storage/dto/PreSignedPostRequest.ts b/backend/src/storage/dto/PreSignedPostRequest.ts
index e7982d77..b336bea7 100644
--- a/backend/src/storage/dto/PreSignedPostRequest.ts
+++ b/backend/src/storage/dto/PreSignedPostRequest.ts
@@ -1,4 +1,5 @@
 import { IsNotEmpty, IsString } from 'class-validator';
+import { IsImageFile } from '../storage.validator';
 
 export class PreSignedPostRequest {
   @IsString()
@@ -7,5 +8,6 @@ export class PreSignedPostRequest {
 
   @IsString()
   @IsNotEmpty()
+  @IsImageFile()
   extension: string;
 }
diff --git a/backend/src/storage/storage.constants.ts b/backend/src/storage/storage.constants.ts
new file mode 100644
index 00000000..9cd1cf9c
--- /dev/null
+++ b/backend/src/storage/storage.constants.ts
@@ -0,0 +1,18 @@
+export const IMAGE_EXTENSIONS = new Set([
+  'jpg',
+  'jpeg',
+  'png',
+  'gif',
+  'bmp',
+  'tiff',
+  'tif',
+  'webp',
+  'svg',
+  'heic',
+  'raw',
+  'cr2',
+  'nef',
+  'arw',
+  'dng',
+  'ico',
+]);
diff --git a/backend/src/storage/storage.controller.ts b/backend/src/storage/storage.controller.ts
index c5340a20..8ea2f7de 100644
--- a/backend/src/storage/storage.controller.ts
+++ b/backend/src/storage/storage.controller.ts
@@ -11,9 +11,7 @@ export class StorageController {
   @Throttle({ default: { limit: 10, ttl: 60000 } })
   @Post('/preSignedPost')
   @UseGuards(JwtAuthGuard)
-  async getPreSignedPostUrl(
-    @Body() preSignedPostRequest: PreSignedPostRequest,
-  ) {
+  async getPreSignedPost(@Body() preSignedPostRequest: PreSignedPostRequest) {
     const { dirName, extension } = preSignedPostRequest;
     return await this.storageService.generatePreSignedPost(dirName, extension);
   }
diff --git a/backend/src/storage/storage.validator.ts b/backend/src/storage/storage.validator.ts
new file mode 100644
index 00000000..0473c2bf
--- /dev/null
+++ b/backend/src/storage/storage.validator.ts
@@ -0,0 +1,25 @@
+import {
+  registerDecorator,
+  ValidationArguments,
+  ValidatorOptions,
+} from 'class-validator';
+import { IMAGE_EXTENSIONS } from './storage.constants';
+
+export function IsImageFile(validationOptions?: ValidatorOptions) {
+  return function (object: object, propertyName: string) {
+    registerDecorator({
+      name: 'IsImageFile',
+      target: object.constructor,
+      propertyName: propertyName,
+      options: validationOptions,
+      validator: {
+        validate(value: any) {
+          return IMAGE_EXTENSIONS.has(value);
+        },
+        defaultMessage(validationArguments?: ValidationArguments): string {
+          return `${validationArguments.value} 는 이미지 확장자가 아닙니다.`;
+        },
+      },
+    });
+  };
+}