Torque ripple is an important factor that affects the servo control precision of BLDC motor, which makes the BLDC motor greatly restricted in the application fields of high accuracy requirements. To solve the problem, the digital current loop is introduced on the basis of the traditional position loop and velocity loop. The digital loop can stabilize the electromagnetic torque by current closed loop control, which can reduce the disturbance of torque ripple so as to improve the servo control precision. Through the analysis of the system model, control system parameters are determined. The design of servo control hardware and software system is completed based on high performance digital signal processor DSP28335. Experimental results show that the introduction of digital current loop can clearly improve the dynamic response performance, and the tracking precision can be improved by nearly 9 times.