In order to explore the influence of the surface morphology of the fuel cell seal on the sealing performance,the Weierstrass-Mandelbrot fractal function was used to characterize the rough surface morphology of the seal,and a two-dimensional finite element model considering the surface morphology of the seal was established based on the Majumdar-Bhushan contact model.The contact characteristics of the smooth surface and the rough surface under the four steps of contact,primary linear loading,unloading and secondary linear loading were studied,and the influence of material hardness of fuel cell seals on the sealing performance was further explored.The results show that the uniformity of stress distribution of the rough surface after second loading is lower than that of the first time,and the uniformity of stress distribution of two times loading are lower than that of the smooth surface.Compared with primary loading,the maximum stress and contact pressure of the rough surface after second loading increases 14.29% and 89.29%,respectively.While the maximum stress and contact pressure of the smooth surface remains almost unchanged.The higher the hardness of the rough surface,the lower the leakage rate,and the reduction rate of the leakage rate decreases with the increasing of hardness.