The system working principle of BVE-200 conveyor/ drive through, BVE-300 conveyor /drive through, BVE-300F Flexible Vehicle Scanner series products is as follows: The system is a top illuminated dual energy X-ray safety inspection system, which uses X-ray penetration scanning to obtain the internal image of the vehicle body, and can identify the contraband hidden in the interlayer, trunk, chassis and other positions without opening the door.