diff --git a/csst_ifs_sim/csst_ifs_sim.py b/csst_ifs_sim/csst_ifs_sim.py
index eddeb9c8f222983e9cf2636b970c142819df5546..5cb21fa9ae4b22022eb8a54682941bcb1bef08aa 100644
--- a/csst_ifs_sim/csst_ifs_sim.py
+++ b/csst_ifs_sim/csst_ifs_sim.py
@@ -2800,7 +2800,7 @@ class IFSsimulator():
                   or self.information['bias2_r'] > 2000 or self.information['bias2_r'] < 100
                   or self.information['bias3_r'] > 2000 or self.information['bias3_r'] < 100
                   or self.information['bias4_r'] > 2000 or self.information['bias4_r'] < 100)
-                  
+
         if checkV:
             self.log.error(
                 'bias value error, it shoub be in [100, 2000]!')