To solve the security control problem of two in-wheel motors front-drive electric vehicles with single motor failure, an electromechanical composite brake control method based on the normal working motor and the electromechanical brake systems is proposed. First, the electromechanical brake system model is established and the brake characteristics is verified by bench test. Then, based on the electric vehicle model and the in-wheel motors model that has been verified by a vehicle test, the instability mechanism of the vehicle with single motor failure is analyzed. Next, taking the yaw rate and the side-slip angle as the state variables, an in-loop controller based on model predictive control theory is designed; taking the yaw angle as the state variable, an outer-loop controller based on fuzzy proportional integral derivative control theory is designed. Finally, the expected stability control is achieved by the distribution of four-wheel brake torque. According to the research, compared with the simple drive motor torque following and motor regenerative brake control, the electromechanical composite brake control can enable the vehicle to offset the effects of instability torque more quickly, so that the vehicle can follow the expected motion trajectory basically and improve the vehicle stability.