diff --git a/src/main/java/com/back/domain/file/entity/AttachmentMapping.java b/src/main/java/com/back/domain/file/entity/AttachmentMapping.java
index 85c2ab1b..104d0f9e 100644
--- a/src/main/java/com/back/domain/file/entity/AttachmentMapping.java
+++ b/src/main/java/com/back/domain/file/entity/AttachmentMapping.java
@@ -9,8 +9,7 @@
 @Getter
 @NoArgsConstructor
 public class AttachmentMapping extends BaseEntity {
-    @ManyToOne(fetch = FetchType.LAZY)
-    @JoinColumn(name = "attachment_id")
+    @OneToOne(fetch = FetchType.LAZY, mappedBy = "attachmentMapping", cascade = CascadeType.ALL, orphanRemoval = true)
     private FileAttachment fileAttachment;
 
     @Enumerated(EnumType.STRING)
diff --git a/src/main/java/com/back/domain/file/entity/FileAttachment.java b/src/main/java/com/back/domain/file/entity/FileAttachment.java
index 41dfbeb6..5c28bc86 100644
--- a/src/main/java/com/back/domain/file/entity/FileAttachment.java
+++ b/src/main/java/com/back/domain/file/entity/FileAttachment.java
@@ -29,8 +29,9 @@ public class FileAttachment extends BaseEntity {
     @JoinColumn(name = "uploaded_by")
     private User user;
 
-    @OneToMany(mappedBy = "fileAttachment", cascade = CascadeType.ALL, orphanRemoval = true)
-    private List<AttachmentMapping> attachmentMappings = new ArrayList<>();
+    @OneToOne(fetch = FetchType.LAZY)
+    @JoinColumn(name = "attachmentMapping_id")
+    private AttachmentMapping attachmentMapping;
 
     public FileAttachment(
             String storedName,
diff --git a/src/test/java/com/back/domain/file/repository/AttachmentMappingRepositoryTest.java b/src/test/java/com/back/domain/file/repository/AttachmentMappingRepositoryTest.java
new file mode 100644
index 00000000..2ad89066
--- /dev/null
+++ b/src/test/java/com/back/domain/file/repository/AttachmentMappingRepositoryTest.java
@@ -0,0 +1,54 @@
+package com.back.domain.file.repository;
+
+import com.back.domain.file.entity.AttachmentMapping;
+import com.back.domain.file.entity.EntityType;
+import com.back.domain.file.entity.FileAttachment;
+import jakarta.persistence.EntityManager;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.mock.web.MockMultipartFile;
+import org.springframework.transaction.annotation.Transactional;
+
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+@SpringBootTest
+@Transactional
+class AttachmentMappingRepositoryTest {
+    @Autowired
+    private FileAttachmentRepository fileAttachmentRepository;
+    @Autowired
+    private AttachmentMappingRepository attachmentMappingRepository;
+    @Autowired
+    private EntityManager em;
+
+    @Test
+    void AttachmentMapping_삭제시_FileAttachment_자동삭제_확인() throws Exception {
+        // given
+        FileAttachment fileAttachment = new FileAttachment(
+                "test",
+                new MockMultipartFile("test", "test", "image", "test".getBytes()),
+                null,
+                "test.URL"
+        );
+        fileAttachmentRepository.save(fileAttachment);
+        System.out.println("현재 저장된 파일 개수 : " + fileAttachmentRepository.findAll().size());
+
+        AttachmentMapping attachmentMapping = new AttachmentMapping(
+                fileAttachment,
+                EntityType.POST,
+                1L
+        );
+        attachmentMappingRepository.save(attachmentMapping);
+
+        // when
+        attachmentMappingRepository.deleteAllByEntityTypeAndEntityId(EntityType.POST, 1L);
+
+        em.flush(); // 즉시 DB에 변경사항 반영
+        em.clear(); // 영속성 컨텍스트 초기화
+
+        // then
+        assertThat(fileAttachmentRepository.findAll().size()).isEqualTo(0);
+    }
+}
\ No newline at end of file