Brushless DC motor is a new mechatronics product. It not only has the characteristics of simple structure, reliable operation and convenient maintenance of asynchronous motor, but also has the advantages of good speed regulation performance of DC motor. Therefore, it is of great theoretical research value and practical application significance to realize brushless DC motor control by using automatic control and embedded system technology. On the basis of mastering the working principle of brushless DC motor and comparing and analyzing the current research results of brushless DC motor control system, this paper focuses on the speed control system of brushless DC motor. The mathematical model of brushless DC motor is established by using phase variables, and the specific speed control method is put forward. On this basis, many characteristics of brushless DC motor are analyzed. Based on the application of brushless DC motor speed regulation system in welding walking equipment, a brushless DC motor speed regulation system based on DSP is designed. The whole DC control system is designed with double closed-loop control. The outer loop of the system is a speed loop and the inner loop is a current loop. A fuzzy PI control method based on control quantity adjustment is designed and applied to speed loop. This method mainly determines whether to adopt fuzzy control method or PI control method with dead zone according to the deviation range between the given speed and the feedback speed of the system. In the fuzzy controller, Mamdani relation generation method is adopted, and the fuzzy control rules based on this system are obtained through a lot of experiments. MATLAB/Simulink tools are used to simulate the system. The simulation results show that the system has fast response speed, basically no overshoot, strong anti-interference ability and high control quality. The system takes TMS320F28 12 digital signal processor as the main controller, and designs power conversion circuit, current sampling circuit, switch circuit, position detection circuit, etc., and realizes the speed control of brushless DC motor. The circuit design is mainly based on the characteristics of high integration, simple circuit, strong anti-interference ability and good robustness, and is applied to brushless DC motor speed regulation system. According to the realization function of the whole system, the software is designed and the specific design flow is given.