The invention provides a control method for the compensation torque of a generator in a range extender. According to the control method, an engine outputs the preset power in the working state so as to meet the requirement of the generated output of the range extender, and the preset power corresponds to the target torque of the engine. The control method comprises the steps of determining a first fluctuation value of the actual output torque and the target torque of the engine under the preset power; determining a torque compensation control factor of the generator so as to obtain a compensation torque value which needs to be compensated for the engine by the generator according to the torque compensation control factor and the first fluctuation value; and determining the actual output torque of the generator according to the target torque value and the compensation torque value so as to enable the actual output torque of the generator and the actual output torque of the engine to be opposite in direction and equal or similar in magnitude. According to the control method, the real-time torque of the generator is adjusted according to different working conditions of the engine so that the purpose of lowering the vibration level of the engine can be achieved, and therefore the NVH performance of the overall range extender can be improved.