Abstract: The proton exchange membrane fuel cell（PEMFC） air system is a nonlinear and strong coupling system, the strong coupling between air mass flow and air pressure into stack have an important effect on the stability of the fuel cell system.In this paper, the simulation model of the fuel cell air supply system were established, a fuzzy decoupling controller was designed on the basis of fuzzy control theory.And the effectiveness of the fuzzy decoupling controller was verified by computational simulation and test.The simulation and test results show that the fuzzy decoupling controller is easy to implement, it can not only provide a good decoupling, but also has good dynamic response and strong robust performance.