For a marine gas turbine generation set, the speed of power turbine must keep constant. Due to the varying load demand, the real and reactive power balance is damaged and thus the speed of power turbine becomes deviated from nominal value. It is necessary for an intelligent controller to keep the speed of power turbine within a permissible range during the varying load operation. The design of an adptive fuzzy PID controller fit for this marine gas turbine generation set were achieved. The simulating experiments were performed at different load conditions to test the effectiveness of the proposed method. Simulation results have shown the improved control performance. The proposed method overcomes the drawbacks of the traditional PID controller and improvement was achieved for the aspects of settling time, oscillations and overshoot.