Retarding brake control system and method

The invention relates to a retarding brake control system and method. An original power system of an electric car is not changed, only a retarding switch provided with a neutral gear and a plurality of non-neutral gears is additionally arranged, a control device connected with the retarding brake control system is sampled, a motor is controlled to output the braking torque corresponding to the gear position where the retarding switch is located, the function of retarding of the electric car is achieved, and the problems that fatigue, heating of a braking system and the like are caused by deceleration, especially frequent braking by a driver in the downhill traveling process are solved. In addition, the control device is in sampling connection with an accelerator pedal and a braking pedal so that the functions of acceleration, emergency braking and the like in the stable decelerating process of the electric car can be achieved.