Batch DWG import and layer properties edit | Community

To try this, go to File > Open, select your DWG file, and see if it meets your requirements. Batch Conversion to PDF and Import: Convert your DWG files to PDF (using “DWG to PDF.pc3” plotter) from AutoCAD. Then, import the resulting PDF file into Illustrator. Make sure that layers are activated for export in the “DWG to PDF.pc3” settings.

https://community.adobe.com/questions-652/batch-dwg-import-and-layer-properties-edit-809765