Abstract: This paper studies the design of a servo control system for an electric motor. A digital controller (DC controller) is constructed using a TI DSP. The control algorithms for the position and speed loops are implemented in the DC controller, and its output is a PWM signal with an adjustable duty cycle, which drives the motor to control its position and speed. The drive circuit mainly consists of a Si9979Cs DC motor control chip and a three-phase bridge composed of six MOSFET power transistors. Finally, all control programs are written in C language, employing a modular structure and exhibiting openness. Keywords: Servo control; Numerical control; DC motor; Brushless DC motor is a new type of servo motor that has developed rapidly in recent years with the rapid advancement of electronic technology. Compared with DC motors, the brushless DC motor uses a commutation circuit instead of the mechanical contact structure composed of a commutator (rectifier) ​​and brushes, thus eliminating commutation sparks, preventing radio interference, and offering long lifespan, reliable operation, and easy maintenance. Compared with AC servo motors, it features simple control and low cost, making it widely used in small electromechanical devices. This paper develops a servo control system for an electric motor based on a digital controller. The hardware circuit can be divided into three parts: the main control circuit module, the power drive circuit module, and the power supply module. The main control circuit module is based on a DSP, and its peripheral circuits mainly include: a debugging simulation interface circuit, an external memory expansion circuit, a serial communication interface circuit, a CAN bus interface, pulse quantity and analog quantity control interfaces, a digital-to-analog conversion circuit, and input/output expansion interfaces. The power drive circuit includes the inverter main circuit and the rotor position detection circuit. The power supply circuit provides the system with multiple DC power supplies of different levels. For details, please click: Research on CNC DC Motor Servo Control System