Due to the variety of gasket shapes,the complex and variable surface contact pressure in engineering,it is difficult to make a quantitative analysis of the sealing performance of different structures quickly by using existing analytical methods.A method to calculate the leakage rate by using compressible Reynolds equation was proposed,in which the change of the leakage gap on the rough surface caused by the sealing contact pressure is equivalent to the parallel leakage gap.This method can quickly calculate the sealing performance under various working conditions.The relationship between contact pressure and leakage gap was calibrated by designing a leak measurement experiment.Based on this relationship,the sealing contact pressure distribution calculated by the finite element model was converted into an equivalent parallel leakage gap distribution,and the leakage rate of the sealing interface is calculated by the Reynolds equation.The accuracy of the leakage prediction method was verified by a D-shaped cross-section gasket.The experimental results prove that this method can calculate the leakage rate of the uneven sealing contact surface quickly and accurately.