Abstract: Dynamic parameter uncertainty and disturbance degrade the tracking performance of a voice coil motor (VCM) servo system. In order to solve these problems, a dynamic model is established in this study. A method called‘adaptive nonsmooth control’ is synthesized by combining the adaptive control and nonsmooth control. Then, the asymptotic stability of the closed-loop system is proven theoretically. Finally, simulations and comparisons are carried out to validate the effectiveness of the proposed method. The simulation results demonstrate that the proposed method has the adaptive compensation capability for uncertainty and rapid convergence property of nonsmooth control. These properties can effectively improve the tracking performance of VCM servo system against uncertainties.