In the paper, a direct yaw-moment control (DYC) strategy is proposed for in-wheel electric vehicles by using second-order sliding mode control technique. The ideal sideslip angle at the center of gravity and yaw rate are first calculated based on a linear two-degree of freedom vehicle model. On this basis, the actual sideslip angle is identified and estimated by constructing a state observer. Then a conventional discontinuous sliding mode DYC controller is first constructed to guarantee that the sideslip angle and yaw rate will approach the ideal ones as closely as possible. To avoid the chattering problem existing in the conventional sliding mode controller, a second-order sliding mode controller is further designed by taking the derivative of the controller as the new control, which implies that the actual control can be the integration of the second-order sliding mode controller. Simulation results verify the effectiveness of the proposed method.