I also try to use Element.SetParameterByName. The value displayed in revit properties is the same as what I feed to the node.
So how I can fix this problem in python script.
It’s hard to say without seeing your code, but a common issue is due to revits internal units being imperial and passing in metric values without first converting to imperial. When you set a value via the API it must be in imperial.
@A.C in addition to @Daniel_Woodcock1’s answer Dynamo nodes (OOTB), uses by default the units of the Revit project