With the ball beam system as the researching object, a single-end hinged ball beam system is designed. In this system, a rolling potentiometer is used to set the ball ideal position on the beam, a high frequency short distance laser displacement sensor is utilized to detect the ball real position, and then the PWM frequency of output is calculated by the MCU internal PID algorithm. When the PWM frequency is send to the ball screw motor drive, the drive make the ball screw motor rotate to realize the ball stay at the initial setting position. The sensitive factors is tested in the Matlab/Simulink environment, the results show that the initial position and sliding friction can influence the system stability.