Abstract: The dynamic mathematical model and system control block diagram of each subsystem of the wind power pitch control system are introduced in detail. The system simulation model based on Matlab Simulink is built. From the fan position command to the speed command, then to the current command, and finally through servo drive to control the pitch motor, so that the blade turning to the corresponding position. A simulation method for studying the control principle of pitch control system is introduced. The simulation gives step signal to analyze the acceleration and deceleration process of pitch motor, and periodic sine wave signal to analyze the position following performance of pitch system. The simulation results verify the correctness of the dynamic mathematical model. The establishment of simulation model and the debugging of simulation parameters are of great significance to the study of control strategy of actual pitch control system.