below … in my python code error image
debug image in dynamo… is below…
why in python code … don’t wokt… PolySurface.ByJoinedSurfaces
is there anyone help me?.. thank you
Looks like the objects you have are Geometry objects, not surfaces, and the wrapper is converting them to surfaces on the way out. Could also be that you’ve got a nested list in some cases. Hard to confirm without a minimal sample code and a dataset though.
Test the object type after Geometry.Intersect.
thank you … you genius 
error is disappeared …
code is changed
before
intersecting_surface= PolySurface.ByJoinedSurfaces(intersecting_surface)
after
intersecting_surface= PolySurface.ByJoinedSurfaces(UnwrapElement(intersecting_surface))
thank you
If you can avoid the unwrap element call I recommend you do; this isn’t super quick in my experience and can give some unintended results. It’s really only built for use on the input directly ( i.e. intersecting_surface = UnwrapElement(IN[1]) ), and even then only in the context of converting from a Dynamo wrapper of a Revit element to a Revit element.
If this is fixing the intersection result you likely need to address the structure directly to catch future failures (i.e. if an intersection return multiple surfaces)