As the process of traditional dynamics modeling for rigid-flexible couple system is complex, this paper introduces the theory of characteristic modeling to simplify the modeling process. Unlike other reduced-order models, characteristic model compresses the high-order information into the characteristic parameters. Therefore, it will not lose model information. In addition, in order to improve the dynamic performance of flexible hub-beam system, a new reaching law of sliding mode control is proposed. The method of commbining sliding mode control and characteristic model is characteristic model-based adaptive dicrete-time sliding mode control(CMADSMC). Experimental results indicate that the designed DSMC can fast track the angle and the vibration of flexible beam will be quickly suppressed.