According to the variation of the average film thickness during the operation of mechanical seal,the reconstructed fractal contact model was used to characterize the surface morphology,and the prediction model of the average film thickness was established combined with the prediction model of the leakage rate of mechanical seal.Mathematica software is used to calculate the leakage rate and average film thickness of the mechanical seal under the given working conditions,and the change trend of the leakage rate and average film thickness after changing the parameters is analyzed.The results show that when the fractal dimension is small,the average film thickness decreases with the decrease of the scale coefficient,the increase of the material coefficient and the increase of the end specific load,but the change of the material coefficient has a small influence on the value of the average film thickness.However,the decrease of the scale coefficient and material coefficient and the increase of the specific load on the end face can lead to the decrease of the leakage rate.When the fractal dimension is larger than 1.69,the influence of specific load and material properties of mechanical seal contact face on the average film thickness and leakage rate can be ignored.