diff --git a/review_agent/file_summary/views.py b/review_agent/file_summary/views.py
index cb701cf..b71ed75 100644
--- a/review_agent/file_summary/views.py
+++ b/review_agent/file_summary/views.py
@@ -1,4 +1,5 @@
 from django.contrib.auth.decorators import login_required
+from django.db import transaction
 from django.db.models import Count, Q
 import json
 import logging
@@ -7,7 +8,14 @@ from pathlib import Path
 from django.http import FileResponse, Http404, JsonResponse
 from django.views.decorators.http import require_http_methods
 
-from review_agent.models import ApplicationFormFillBatch, Conversation, ExportedSummaryFile, FileAttachment, Message
+from review_agent.models import (
+    ApplicationFormFillBatch,
+    Conversation,
+    ExportedSummaryFile,
+    FileAttachment,
+    Message,
+    RegulatoryReviewBatch,
+)
 from review_agent.models import FileSummaryBatch, WorkflowEvent
 from review_agent.notifications.presenter import serialize_notification_records
 from .events import serialize_event
@@ -152,7 +160,10 @@ def conversation_list(request):
 @login_required
 def conversation_detail(request, conversation_id: int):
     conversation = _conversation_for_user(request.user, conversation_id)
-    conversation.delete()
+    with transaction.atomic():
+        ApplicationFormFillBatch.objects.filter(conversation=conversation).delete()
+        RegulatoryReviewBatch.objects.filter(conversation=conversation).delete()
+        conversation.delete()
     return JsonResponse({"ok": True, "conversation_id": conversation_id})
 
 
diff --git a/tests/test_file_summary_views.py b/tests/test_file_summary_views.py
index b6b277f..c4a8a83 100644
--- a/tests/test_file_summary_views.py
+++ b/tests/test_file_summary_views.py
@@ -10,6 +10,7 @@ from review_agent.models import (
     FileAttachment,
     FileSummaryBatch,
     Message,
+    RegulatoryReviewBatch,
     WorkflowNodeRun,
 )
 
@@ -269,6 +270,39 @@ def test_conversation_delete_api_removes_owned_conversation(client, django_user_
     assert Conversation.objects.filter(pk=other_conversation.pk).exists()
 
 
+def test_conversation_delete_api_removes_protected_workflow_dependents(client, django_user_model):
+    user = django_user_model.objects.create_user(username="owner", password="pass")
+    conversation = Conversation.objects.create(user=user, title="待删除")
+    summary_batch = FileSummaryBatch.objects.create(
+        conversation=conversation,
+        user=user,
+        batch_no="FS-DELETE-PROTECTED",
+    )
+    regulatory_batch = RegulatoryReviewBatch.objects.create(
+        conversation=conversation,
+        user=user,
+        source_summary_batch=summary_batch,
+        batch_no="RR-DELETE-PROTECTED",
+    )
+    form_batch = ApplicationFormFillBatch.objects.create(
+        conversation=conversation,
+        user=user,
+        source_summary_batch=summary_batch,
+        source_regulatory_batch=regulatory_batch,
+        batch_no="AFF-DELETE-PROTECTED",
+    )
+    client.force_login(user)
+
+    response = client.delete(reverse("review_agent_conversation_detail", args=[conversation.pk]))
+
+    assert response.status_code == 200
+    assert response.json()["ok"] is True
+    assert not Conversation.objects.filter(pk=conversation.pk).exists()
+    assert not FileSummaryBatch.objects.filter(pk=summary_batch.pk).exists()
+    assert not RegulatoryReviewBatch.objects.filter(pk=regulatory_batch.pk).exists()
+    assert not ApplicationFormFillBatch.objects.filter(pk=form_batch.pk).exists()
+
+
 def test_conversation_delete_api_rejects_unowned_conversation(client, django_user_model):
     user = django_user_model.objects.create_user(username="owner", password="pass")
     other = django_user_model.objects.create_user(username="other", password="pass")