diff --git a/csst_common/data_manager.py b/csst_common/data_manager.py
index 6bb884f3245ab74daed1afb0bff722e011e05a81..74096f18c1ff91f225a4dd34431e8d030acea699 100644
--- a/csst_common/data_manager.py
+++ b/csst_common/data_manager.py
@@ -578,6 +578,19 @@ class CsstMsDataManager:
         else:
             return self.custom_flat.format("flat", detector)
 
+    def get_shutter(self, detector=6):
+        """ get flat data """
+        if self.custom_flat is None:
+            return os.path.join(
+                self.path_aux,
+                "C6.2_ref_mbi",
+                "CSST_MSC_MS_SHUTTER_{:02d}_{:04d}.fits".format(
+                    detector, 1 if self.ref_version is None else self.ref_version
+                )
+            )
+        else:
+            return self.custom_flat.format("flat", detector)
+
     def get_axeconf(self):
         return os.path.join(self.path_aux, "axeconf")  # "/home/csstpipeline/L1Pipeline/aux/axeconf"