Abstract: The control method that combined variable speed and variable displacement is a new type of cubage control. It has the advantages of high efficiency and relative fast response. But its multiplicative essential nonlinear property causes trouble to control. To the pump controlled motor speed system with frequency inverter and variable displacement, its mathematical model was established. To the problem of essential nonlinear property, the exact feedback linearization method was put forward in the linear process, and the motor speed sliding mode control(SMC) with integral sliding surface was designed. Considering the system with multiple parameter, the parameters were variable and difficult to be determined. All this leaded to the more chatting phenomenon in the output. to debase it, the adaptive fuzzy SMC was used to improve it, and its stability was proved. The anti disturb ability and sinusoidal track ability simulation were done. The simulation results show the validity of this control method.