Now KiCAD has a dxf import issue:
DXF file import is incorrect (#14210) · Issues · KiCad / KiCad Source Code / kicad · GitLab
This issue is a very serious issue, sometime I can’t continue working because the imported edge cuts is totaly wrong, and this issue solving time has been delayed time and time:
But now, I find a way to get the edge of PCB which avoids dxf impot issue-- To use KiCADStepUp.
The KiCADStepUp can get the edge from 3D file and export it to KiCAD PCB file directly, it avoid this issue perfectly.
Thanks to KiCADStepUp again.