Local environmental protection department, online query platform.

1. You can go to the environmental protection department where the excavator is located, provide the license plate number or environmental protection number of the excavator, and consult the staff for license plate information. The environmental protection department usually has a corresponding database where you can query the detailed information of the excavator's environmental protection license plate.

2. Environmental protection departments in some areas provide an online query platform. You can enter the excavator license plate number or environmental protection number on the website to query license plate information.