This paper proposed a combined method for wind energy conversion system using pressure coupling (PC) hydrostatic transmission. The operation strategy is the combination of maximizing power point tracking at the input power and stabilizing the output power. The maximum power point tracking method is to control the turbine speed for tracking the optimal tip speed ratio (TSR). For maximizing the input power, a PID controller and a sliding mode controller are applied for speed control to track a predefined speed that is calculated from the optimal TSR. The output power is stabilized by using a high-pressure accumulator for accumulating and compensating the power. The driven speed of the generator is controlled by the PC principle, using a PID controller and an adaptive fuzzy sliding mode controller. Experiments are carried out to verify the proposed method. The overall efficiency in several wind speed profiles is about 40%.