The present invention involves control devices a car steering lamps, and it belongs to the area of car manufacturing technology. It includes as follows. Used in a signal collection module that could collect the signal of environmental light intensity and the signal of car steering lamp switching, and then change the signal to be of high-low electrical level digital signal. Used in a signal treatment module that could logically judge the digital signal and then acquire a group of control signal. Used in the relay driver module that could convert the control signal to the relay driver signal; Used in the car steering lamp control module that could receive control signal and control the opening and closing of steering lamp through relay. The control device of this invention, automatically judge whether or not the lights are open, opening time signal and external light intensity signal, so steering lamp would have three main function: daytime normal steering instruction, night normal steering lighting, automatic close of the steering lamp forgotten shut down. The control device of this invention also has simple structure and could be easy to be realized; It would be low cost, and could be easy to be implemented, so it could be easily popularized and widely applied.