This paper considers the discrete-time quasi-sliding mode control for a class of uncertain switched systems. Since the input matrices are different, a weighted sum approach is proposed such that a common sliding surface is designed. Moreover, by designing a sliding mode control law, the state trajectories are driven into a certain band of the sliding surface. Furthermore, to guarantee the exponential stability of the sliding mode dynamics, a sufficient condition based on the average dwell time technology is given. Finally, a simulation is given to demonstrate the efficiency of the proposed method.