diff --git a/src/main/java/mvp/deplog/domain/comment/application/CommentService.java b/src/main/java/mvp/deplog/domain/comment/application/CommentService.java
index d5d1576..0cb46f6 100644
--- a/src/main/java/mvp/deplog/domain/comment/application/CommentService.java
+++ b/src/main/java/mvp/deplog/domain/comment/application/CommentService.java
@@ -29,59 +29,65 @@ public class CommentService {
     public SuccessResponse<List<CommentListRes>> getCommentList(Long postId){
         Post post = postRepository.findById(postId)
                 .orElseThrow(() -> new IllegalArgumentException("해당하는 아이디의 게시글이 없습니다: " + postId));
-        List<Comment> commentList = commentRepository.findByPost(post);
+
+        List<Comment> commentList = commentRepository.findByPostAndParentCommentIsNull(post);
+        List<Comment> replyList = commentRepository.findByPostAndParentCommentIsNotNull(post);
 
         List<CommentListRes> commentDetails = new ArrayList<>();
 
         for(Comment comment : commentList) {
-            Avatar avatar;
-            if (comment.isUseNickname()) {
-                avatar = Avatar.builder()
-                        .avatarFace(null)
-                        .avatarBody(null)
-                        .avatarEyes(null)
-                        .avatarNose(null)
-                        .avatarMouth(null)
-                        .build();
-            } else {
-                Member member = comment.getMember();
-                avatar = Avatar.builder()
-                        .avatarFace(member.getAvatarFace())
-                        .avatarBody(member.getAvatarBody())
-                        .avatarEyes(member.getAvatarEyes())
-                        .avatarNose(member.getAvatarNose())
-                        .avatarMouth(member.getAvatarMouth())
-                        .build();
-            }
+            Avatar avatar = commentAvatar(comment);
+
+            CommentListRes commentListRes = CommentListRes.builder()
+                    .commentId(comment.getId())
+                    .avatar(avatar)
+                    .nickname(comment.getNickname())
+                    .createdDate(comment.getCreatedDate().toLocalDate())
+                    .content(comment.getContent())
+                    .replyList(new ArrayList<>())   // 대댓글 리스트 초기화
+                    .build();
+
+            commentDetails.add(commentListRes);
+        }
 
-            if(comment.getParentComment() == null){
-                CommentListRes commentListRes = CommentListRes.builder()
-                        .commentId(comment.getId())
-                        .avatar(avatar)
-                        .nickname(comment.getNickname())
-                        .createdDate(comment.getCreatedDate().toLocalDate())
-                        .content(comment.getContent())
-                        .replyList(new ArrayList<>())   // 대댓글 리스트 초기화
-                        .build();
+        for(Comment reply : replyList) {
+            Avatar avatar = commentAvatar(reply);
 
-                commentDetails.add(commentListRes);
-            } else {
-                ReplyListRes replyListRes = ReplyListRes.builder()
-                        .commentId(comment.getId())
-                        .parentCommentId(comment.getParentComment().getId())
-                        .avatar(avatar)
-                        .nickname(comment.getNickname())
-                        .createdDate(comment.getCreatedDate().toLocalDate())
-                        .content(comment.getContent())
-                        .build();
+            ReplyListRes replyListRes = ReplyListRes.builder()
+                    .commentId(reply.getId())
+                    .parentCommentId(reply.getParentComment().getId())
+                    .avatar(avatar)
+                    .nickname(reply.getNickname())
+                    .createdDate(reply.getCreatedDate().toLocalDate())
+                    .content(reply.getContent())
+                    .build();
 
-                commentDetails.stream()
-                        .filter(parentComment -> parentComment.getCommentId().equals(comment.getParentComment().getId()))
-                        .findFirst()
-                        .ifPresent(parentComment -> parentComment.getReplyList().add(replyListRes));
-            }
+            commentDetails.stream()
+                    .filter(parentComment -> parentComment.getCommentId().equals(reply.getParentComment().getId()))
+                    .findFirst()
+                    .ifPresent(parentComment -> parentComment.getReplyList().add(replyListRes));
         }
 
         return SuccessResponse.of(commentDetails);
     }
+
+    private Avatar commentAvatar(Comment comment){
+        if(!comment.isUseNickname()) {
+            Member member = comment.getMember();
+            return Avatar.builder()
+                    .avatarFace(member.getAvatarFace())
+                    .avatarBody(member.getAvatarBody())
+                    .avatarEyes(member.getAvatarEyes())
+                    .avatarNose(member.getAvatarNose())
+                    .avatarMouth(member.getAvatarMouth())
+                    .build();
+        }
+        return Avatar.builder()
+                .avatarFace(null)
+                .avatarBody(null)
+                .avatarEyes(null)
+                .avatarNose(null)
+                .avatarMouth(null)
+                .build();
+    }
 }
diff --git a/src/main/java/mvp/deplog/domain/comment/domain/repository/CommentRepository.java b/src/main/java/mvp/deplog/domain/comment/domain/repository/CommentRepository.java
index 8da159e..5ea1b61 100644
--- a/src/main/java/mvp/deplog/domain/comment/domain/repository/CommentRepository.java
+++ b/src/main/java/mvp/deplog/domain/comment/domain/repository/CommentRepository.java
@@ -8,7 +8,15 @@
 
 public interface CommentRepository extends JpaRepository<Comment, Long> {
 
-    List<Comment> findByPost(Post post);
+    // 댓글 목록 조히
+    List<Comment> findByPostAndParentCommentIsNull(Post post);
 
-    void deleteByPost(Post post);
+    // 대댓글 목록 조회
+    List<Comment> findByPostAndParentCommentIsNotNull(Post post);
+
+    // 대댓글 삭제
+    void deleteByPostAndParentCommentIsNotNull(Post post);
+
+    // 댓글 삭제
+    void deleteByPostAndParentCommentIsNull(Post post);
 }
diff --git a/src/main/java/mvp/deplog/domain/comment/dto/request/CreateCommentReq.java b/src/main/java/mvp/deplog/domain/comment/dto/request/CreateCommentReq.java
index 9d4c25d..606527f 100644
--- a/src/main/java/mvp/deplog/domain/comment/dto/request/CreateCommentReq.java
+++ b/src/main/java/mvp/deplog/domain/comment/dto/request/CreateCommentReq.java
@@ -1,6 +1,7 @@
 package mvp.deplog.domain.comment.dto.request;
 
 import io.swagger.v3.oas.annotations.media.Schema;
+import jakarta.validation.constraints.NotBlank;
 import lombok.Data;
 
 @Data
@@ -13,11 +14,13 @@ public class CreateCommentReq {
     private Long postId;
 
     @Schema(type = "String", example = "**댓글 내용**", description = "댓글 내용입니다.")
+    @NotBlank
     private String content;
 
     @Schema(type = "String", example = "닉네임", description = "닉네임입니다.")
+    @NotBlank
     private String nickname;
 
-    @Schema(type = "boolean", example = "true", description = "닉네임 사용 체크박스 체크 여부입니다. 회원이 체크 안한 경우, 비회원의 경우 모두 true입니다. 회원이 누른 경우만 falseh입니다.")
+    @Schema(type = "boolean", example = "true", description = "닉네임 사용 체크박스 체크 여부입니다. 회원이 체크 안한 경우, 비회원의 경우 모두 true입니다. 회원이 누른 경우만 false입니다.")
     private boolean useNicknameChecked;
 }
diff --git a/src/main/java/mvp/deplog/domain/comment/presentation/CommentApi.java b/src/main/java/mvp/deplog/domain/comment/presentation/CommentApi.java
index 6fd3995..c3b9d5f 100644
--- a/src/main/java/mvp/deplog/domain/comment/presentation/CommentApi.java
+++ b/src/main/java/mvp/deplog/domain/comment/presentation/CommentApi.java
@@ -8,6 +8,7 @@
 import io.swagger.v3.oas.annotations.responses.ApiResponse;
 import io.swagger.v3.oas.annotations.responses.ApiResponses;
 import io.swagger.v3.oas.annotations.tags.Tag;
+import jakarta.validation.Valid;
 import mvp.deplog.domain.comment.dto.request.CreateCommentReq;
 import mvp.deplog.domain.comment.dto.response.CommentListRes;
 import mvp.deplog.global.common.Message;
@@ -40,7 +41,7 @@ public interface CommentApi {
     @PostMapping
     ResponseEntity<SuccessResponse<Message>> createComment(
             @Parameter(description = "Access Token을 입력해주세요.", required = true) @AuthenticationPrincipal UserDetailsImpl userDetails,
-            @Parameter(description = "Schemas의 CommentReq를 참고해주세요.", required = true) @RequestBody CreateCommentReq createCommentReq
+            @Parameter(description = "Schemas의 CommentReq를 참고해주세요.", required = true) @Valid @RequestBody CreateCommentReq createCommentReq
     );
 
     @Operation(summary = "댓글 목록 조회 API", description = "해당 게시글을 댓글 목록을 조회합니다.")
diff --git a/src/main/java/mvp/deplog/domain/comment/presentation/CommentController.java b/src/main/java/mvp/deplog/domain/comment/presentation/CommentController.java
index 28a97a9..e7ac15e 100644
--- a/src/main/java/mvp/deplog/domain/comment/presentation/CommentController.java
+++ b/src/main/java/mvp/deplog/domain/comment/presentation/CommentController.java
@@ -1,5 +1,6 @@
 package mvp.deplog.domain.comment.presentation;
 
+import jakarta.validation.Valid;
 import lombok.RequiredArgsConstructor;
 import mvp.deplog.domain.comment.application.CommentService;
 import mvp.deplog.domain.comment.application.CreateCommentService;
@@ -26,7 +27,8 @@ public class CommentController implements CommentApi {
 
     @Override
     @PostMapping
-    public ResponseEntity<SuccessResponse<Message>> createComment(@AuthenticationPrincipal UserDetailsImpl userDetails, @RequestBody CreateCommentReq createCommentReq) {
+    public ResponseEntity<SuccessResponse<Message>> createComment(@AuthenticationPrincipal UserDetailsImpl userDetails,
+                                                                  @Valid @RequestBody CreateCommentReq createCommentReq) {
         CreateCommentService createCommentService = createCommentServiceFactory.find(userDetails, createCommentReq.getParentCommentId());
         return ResponseEntity
                 .status(HttpStatus.CREATED)
diff --git a/src/main/java/mvp/deplog/domain/post/application/PostService.java b/src/main/java/mvp/deplog/domain/post/application/PostService.java
index be33a6a..4f55a61 100644
--- a/src/main/java/mvp/deplog/domain/post/application/PostService.java
+++ b/src/main/java/mvp/deplog/domain/post/application/PostService.java
@@ -222,8 +222,11 @@ public SuccessResponse<Message> deletePost(Long memberId, Long postId) {
             throw new UnauthorizedException("본인이 작성한 게시글이 아니므로 삭제할 수 없습니다.");
         }
 
+        // 게시글 내 대댓글 삭제
+        commentRepository.deleteByPostAndParentCommentIsNotNull(post);
+
         // 게시글 내 댓글 삭제
-        commentRepository.deleteByPost(post);
+        commentRepository.deleteByPostAndParentCommentIsNull(post);
 
         // 게시글 내 태그 삭제
         taggingRepository.deleteByPost(post);