With the development of science and technology, digital control systems are more widely used, which is more conducive to the development of intelligent power locomotives. In the speed control process of electric traction DC motor, considering the stability, rapidity, accuracy and other requirements of speed control, digital position type PID control strategy is adopted.This study first models the power traction DC motor and analyzes the performance of the system. In order to improve the performance index of the system, a digital PID control strategy is adopted.MATLAB simulation results show that the controller has good speed and stability for the speed control of electric traction DC motor.