diff --git a/csst_mci_sim/csst_mci_sim.py b/csst_mci_sim/csst_mci_sim.py
index 3d37fbd0e5f9c6772307e365567e0f1189985dd4..3603813350100689c73982a1fa483c7634cc8b41 100644
--- a/csst_mci_sim/csst_mci_sim.py
+++ b/csst_mci_sim/csst_mci_sim.py
@@ -1715,7 +1715,7 @@ class MCIsimulator():
         ############ load star data catlog #####################            
         ##starcat='selection_20230517_concat.csv'
         
-        starcat='star_catlog'
+        starcat='star_catlog.csv'
         
         ##starcat='GaiaSource_675688-675713.csv'