Vehicle automatic clutch can be automatically separated and combined with the operation condition and the driver's intention. The clutch control performance is good or bad, which directly affects the longitudinal comfort and fuel economy of the vehicle. Therefore, it has important industrial application value to study the control problem of the electric control clutch. Generally speaking, clutch control to solve two problems: first, the combination of the law of the clutch; the two is the implementation of the law to track the combination. So the whole controller is divided into the upper controller and the lower controller. Shen Shuiwen et al. Discussed the upper layer controller to solve the clutch problem. Because of the nonlinear, time delay, external disturbance and parameter perturbation, the system has some difficulties in tracking the clutch. A sliding mode variable structure controller is designed in this paper. Motor drive clutch executing mechanism modeling DC brushless motor position servo system, which includes inner and outer rings of two controller, the inner loop is a by a sinusoidal current control of the PWM inverter; outer ring is a variable structure controller for generates a control signal input loop. X for clutch separation bearing reference displacement, which represents the ideal combination of the clutch, from the upper controller, that is, the clutch controller, DC brushless servo motor for three-phase permanent magnet synchronous motor. It is worth mentioning that the diaphragm spring in the clutch plays an important and special role. Because of its special structure, a release lever and the spring action. At the same time, its special nonlinear characteristics in the driven plate friction plate wear, still can reliably transfer torque, and make the pedal control light.