Temperature affects the sealing performance and mechanical behavior of proton exchange membrane fuel cell (PEMFC),thus affecting their service life and reliability.To study the sealing performance and mechanical behavior of PEMFC under thermodynamic coupling,two-dimensional models of PEMFC single-cell and multi-cell structures were established to study the stress-strain distribution of the sealing system at different operating temperatures.The effects of rubber sealing ring compression ratio,bipolar plate misalignment and sealing gasket size on the sealing performance and mechanical properties of the PEMFC were discussed.The results show that temperature has a significant effect on the Mises stress of the sealing gasket and the contact pressure of the membrane electrode assembly (MEA) frame.The sealing performances of single-cell and multi-cell structures at different operating temperatures are similar,and the differences in stress and contact pressure distribution are not significant.Therefore,the research conclusion of single-cell structure can be extended to multi-cell structure.The fuel cell sealing performance is improved with increasing compression ratio and size of the rubber sealing ring.The misalignment of the bipolar plates exacerbates the deformation of the MEA frame.The high stress area appears inside the cross section of the rubber sealing ring,which can easily lead to local stress concentration and sealing failure.