The application discloses a method, system and related device of implementing vehicle automatically weighing, so as to achieve the automatically weighing of the unmanned vehicle. The method includes: controlling, by a vehicle controller, a vehicle to drive automatically and stop at a weighing position; weighing, by a weighbridge sensor, the vehicle when sensing the vehicle stopping at the weighing position, and sending weighing end information to the vehicle controller; and controlling, by the vehicle controller, the vehicle to start and leave the weighing position when receiving the weighing end information.