diff --git a/B06_Section/B06_Section_Router_Confirm.py b/B06_Section/B06_Section_Router_Confirm.py
index 3a23ceddf..e535d552f 100644
--- a/B06_Section/B06_Section_Router_Confirm.py
+++ b/B06_Section/B06_Section_Router_Confirm.py
@@ -186,6 +186,18 @@ async def _recompute_stored_designs(project_id: UUID, route_id: int) -> None:
         )
 
 
+def _prune_cross_files(project_root: Path, longitudinal_file_path: str) -> None:
+    """측점을 고친 뒤 옛 cross_*.json 을 지움 — GET 은 안 지우므로 쓰는 쪽(저장 · 확정)이 맡음."""
+    from B05_Profile.B05_Profile_Engine_Sections import prune_stale_cross_files
+
+    path = project_root / longitudinal_file_path
+    try:
+        stations = json.loads(path.read_text(encoding="utf-8")).get("stations") or []
+    except (OSError, ValueError, AttributeError):
+        return  # 측점을 못 읽으면 안 지움(오삭제 막음)
+    prune_stale_cross_files(path.parent.parent / "cross_sections", stations)
+
+
 async def _prebuild_corridor(project_id: UUID, route_id: int, project_root: Path) -> None:
     """3D 길 모형을 서버 Node 가 지어 남긴다(342-2) — 정본이 다시 선 [저장] · [확정] 끝.
 
@@ -261,6 +273,10 @@ async def save_sections(
             missing = await get_cross_sections_missing_design_chainages(connection, route_id)
 
         project_root = Path(resolve_stored_project_path(stored_path))
+        # 측점 맞춤이 지운 자리의 옛 횡단 파일 정리(쓰는 쪽 몫)
+        await asyncio.to_thread(
+            _prune_cross_files, project_root, str(existing["longitudinal_file_path"])
+        )
         rowless = missing + await asyncio.to_thread(
             _rowless_station_chainages,
             project_root,
@@ -341,6 +357,10 @@ async def confirm_sections(
             known = await get_cross_section_chainages(connection, route_id)
         marks.append(("조회(종단·경로·미지정 측점)", time.perf_counter()))
         project_root = Path(resolve_stored_project_path(stored_path))
+        # 측점 맞춤이 지운 자리의 옛 횡단 파일 정리(쓰는 쪽 몫)
+        await asyncio.to_thread(
+            _prune_cross_files, project_root, str(existing["longitudinal_file_path"])
+        )
         # 행 자체가 없는 측점(구조물 등 비정규)도 확정 대상에 넣는다 — 정본이 없으면
         # 조회 때마다 프리뷰가 다시 계산돼 3D·수량이 확정 결과가 아니게 된다(2026-08-24).
         missing = missing + await asyncio.to_thread(
diff --git a/resources/tester/test_346_3_route_save.py b/resources/tester/test_346_3_route_save.py
index ce90c8efd..3a0618cb5 100644
--- a/resources/tester/test_346_3_route_save.py
+++ b/resources/tester/test_346_3_route_save.py
@@ -539,3 +539,23 @@ def test_계획고_옮김은_앞_그대로_뒤_밂(tmp_path, monkeypatch):
     assert edits["40.000"] == 0.7  # 바뀐 구간 앞 — 그대로
     assert "200.000" not in edits  # 바뀐 구간 안 — 새 지반
     assert edits[f"{380.0 + delta:.3f}"] == 0.3  # 뒤 — 길이 차만큼 밂
+
+
+def test_저장_확정이_옛_횡단_파일을_지움(tmp_path):
+    from B05_Profile.B05_Profile_Engine_Sections import cross_filename
+
+    long_path = tmp_path / "B06_Section" / "longitudinal" / "longitudinal.json"
+    cross_dir = tmp_path / "B06_Section" / "cross_sections"
+    long_path.parent.mkdir(parents=True)
+    cross_dir.mkdir(parents=True)
+    long_path.write_text(json.dumps({"stations": [{"chainage_m": 0.0}, {"chainage_m": 20.0}]}))
+    for at in (0.0, 20.0, 37.0):
+        (cross_dir / cross_filename(at)).write_text("{}")
+    b06_confirm._prune_cross_files(tmp_path, "B06_Section/longitudinal/longitudinal.json")
+    assert sorted(p.name for p in cross_dir.glob("cross_*.json")) == sorted(
+        cross_filename(at) for at in (0.0, 20.0)
+    )
+    source = (ROOT / "B06_Section" / "B06_Section_Router_Confirm.py").read_text("utf-8")
+    for name in ("async def save_sections(", "async def confirm_sections("):
+        body = source[source.index(name) :]
+        assert body.index("_stand_patch_stations(") < body.index("_prune_cross_files,")