Abstract: To track the target quickly and accurately, based on the analysis of the four degree of freedom nonlinear dynamic model, and with Lyapunov stability analysis method, a sliding mode variable structure control method for autonomic underwater vehicle (AUV) was proposed. A genetic-sliding mode controller was designed, and its parameters were optimized with genetic algorithm to reduce vibration. In addition, the global optimal solution was chosen dynamically, so as to improve the convergence speed, and implement the motion state real-time adjustment. The simulation results demonstrat that the method can obtain the global optimal solution efficiently with better self-adaptive ability and can realize the trajectory tracking of the AUV efficiently.