Abstract: Considering the high order and model complexity for rigid-flexible couple system,character modeling theory is used to simplify the modeling process. In addition,considering the system's uncertainties,a characteristic model-based adaptive discrete-time sliding mode control with proportional integral derivative (PID) sliding surface is proposed. With this controller,the system can track the angular displacement of the center rigid rapidly and suppress the vibration of flexible parts soon. Compared with the traditional PI (proportional integraal) and fuzzy PI,the results of physical experiments show that angular displacement tracking has smaller overshot and better suppression effect for the vibration of flexible beams with the proposed control.