Abstract: A fuzzy PID controller is designed in this paper to achieve the high-accuracy of a certain type of pressure vessels with superior rapid control and steady-state control functions. Specifically， the fuzzy PID control strategy is applied on the AMEsim simulating platform， and the large inertia of the pressure vessel as well as the nonlinearity and hysteresis of the pilot pneumatic regulating valve are also considered during the design process. The controller is seen to have decent dynamic performance in fuzzy control and steady PID control， and its simulated dynamic-static accuracy successfully meets the deep-ocean pressure requirement.