In this paper, a switched sliding mode control(SSMC) method with three sliding surfaces is proposed for a class of uncertain affine nonlinear systems. The system extended dynamic space is divided into three subspaces by the three sliding surfaces. The sliding region consists of two subspaces. The sliding region satisfies the reaching condition and the sliding condition with appropriate switching rules and switching gains. By using SSMC, the control law is discontinuous only within a certain range near the origin while the switching gain of the control law is reduced. Such characteristic is beneficial to suppress the chattering phenomenon. For practical application, a feasible design method is also designed which can guarantee system states ultimately bounded stable. By adjusting the design parameters, the size of the ultimate bound can be adjusted. Simulation results show that SSMC has high control precision while suppressing chattering.