The invention discloses a vehicle-mounted electric gear shift test bed comprising servo electric cylinders, gearshift mechanical arms, a gearshift lever, a gearshift lever installation fixation device, a vehicle-mounted gearshift test support bench, and a test control computer. The two servo electric cylinders are arranged; the bodies of the two servo electric cylinders are installed at the vehicle-mounted gearshift test support bench in parallel. One end of each of the two gearshift mechanical arms is connected with a servo electric cylinder lead screw by a knuckle bearing and the other end is connected with the gearshift lever installation fixation device by a knuckle bearin; and the lengths of the gearshift mechanical arms can be adjusted. The gearshift lever installation fixation device is installed at the gearshift lever. The vehicle-mounted gearshift test support bench is fixed at driving seat and copilot seat guide rails. The two servo electric cylinders make action according to an instruction sent out by the test control computer to complete gear selection and shift operations. Therefore, related tests of the speed changer can be completed on the overall vehicle; the objectivity and accuracy of test data can be guaranteed; the fatigue degree of the driver can be reduced; and any injury on the test staff by the severe environment can be reduced.