Abstract: In order to explore the influence of inlet humidity of a Proton Exchange Membrane Fuel Cell (PEMFC) on its output performance,this paper builds a PEMFC analysis model based on COMSOL Multiphysics and Matlab platform.Then,the polarization curve of PEMFC is obtained and the output performance is analyzed.The analysis results show that increasing the inlet humidity is helpful in improving the water content and conductivity of the proton exchange membrane,reducing the ohmic impedance,and increasing the output voltage and power of the cell.The analysis results are also helpful in understanding the influence law of the inlet humidity on the output performance of fuel cells,which provides guiding significance for the practical application of PEMFC.