As the angle conversion accuracy of the current cradle head control system is not high, a three-axis control system based on STM32F103ZET6 is designed.The system uses MPU6050 triaxial gyroscope to collect the information of rolling angle, pitching angle and deviation angle of the cradle head, and communicates with STM32 through the IIC interface.At the same time, the upper computer sends the set value to STM32 through USART serial port and compares it with the angle collected by the gyroscope to obtain the control value. The incremental PID control algorithm figure out the control value to control the rotation of 28BYJ-48 stepper motor which adopts four-phase eight-beat method to realize the angle convertion.By building hardware for testing, the system can realize the precise positioning of the stepping motor with the high system accuracy.