Orthogonal test method can reduce test times, shorten test cycles and find multi-factors optimization scheme quickly. In this study, the operation parameters of PEMFC were optimized by the orthogonal experiment method, which met the requirements of the fuel cell parameter optimization test under steady working condition. With the help of four factors and three levels orthogonal table, nine orthogonal experiments were designed to study the influences of fuel cell's operating temperature, gas inlet pressure, relative humidity and oxidant stoichiometric ratio on the performance of PEMFC. On the basis of the polarization curve, local current density distributions and electrochemical impedance spectroscopy (EIS) technologies, the correctness of the conclusions obtained from the orthogonal experiment was verified. In the study, the optimization combinations of the operating parameters in different current density loads are listed. The test results show that, the effect of air stoichiometric ratio on PEMFC performance is the largest under the condition of medium and high current density, while the effect of gas inlet pressure on PEMFC performance is the largest under the condition of low current density. On the other hand, the operating temperature and air RH have little impact on the performance of PEMFC. Furthermore, the mechanism of predominant parameters on the performance of fuel cell is discussed. •The influence degrees of each parameter on the performance of PEMFC were sorted by the orthogonal method.•Polarization curves and EIS were adopted to verify the conclusions obtained from the orthogonal experiment.•Local current density distribution was used to analyze reasons for the performance in different tests.