An electrical active roll stabilizer has been designed and developed for improving the vehicle anti-roll performance. The motor actuator composed by a switched reluctance motor(SRM) and a harmonic gear reducer is a key component of the active roll stabilizer to generate the active anti-roll torque. There are three main steps of studying the performance of the motor actuator in this paper. Firstly, the accurate mathematical model of SRM is built in Matlab/Simulink using the data of magnetization characteristics calculated by the finite element analysis using Maxwell/RMxprt. Secondly, the full vehicle roll model is set up and the sliding mode controller based on feedback linearization for roll control is designed in Matlab/Simulink. The controller calculates the real-time ideal anti-roll torques of the front and rear stabilizers based on the lateral acceleration and roll angle. Finally, the vehicle steering model is established in Carsim and the control co-simulation is carried out by the combination of Matlab/Simulink and Carsim. The co-simulation results show that the body roll motion due to the lateral acceleration while steering was substantially reduced by sliding model controller compared with passive roll stabilizer and PID controller. The results also verify the validity of the controller and indicate that the motor actuator can effectively realize the ideal anti-roll torques.