Abstract: Limited by external operating conditions and the coupling mechanism of internal multi-physics parameters, the accurate mechanism modeling of proton exchange membrane fuel cells has become the bottleneck of its development and application. In this paper, a quasi-one-dimensional stack dynamic model is constructed by exploring the multi-physical coupling relationship of "electricity-heat-flow" domain inside the fuel cell. Based on single-parameter sensitivity and multi-parameter sensitivity analysis, the sensitivity indicators of different model parameters are obtained, and the weight analysis of some key parameters in the modeling is completed. In order to verify the model accuracy and the influence of coupling parameter changes on the output characteristics, this paper conducts load and parameter changes experiments on the basis of building a Ballard NEXA 1.2 kW fuel cell test platform. The results show that the constructed model can simulate the characteristics of the stack accurately, and the changes of the symmetry factor, the activation area and the pressure coefficient have a great influence on the output of the stack. This paper can provide a theoretical basis for the testing and modification of fuel cell stacks, and simulate the decay and changes of main parameters in the process of stack fault and aging, which effectively reduces the complexity of the model and the simulation calculation burdens.