The arrangements of elliptical micropores with different orientation angles on the mechanical seal face have different impact on the opening force and leakage rate.The design demands for the opening force and leakage rate are also different under different working conditions.Therefore,the doubleobjective evaluation model should be used to evaluate the influence of micropore arrangements on the sealing performance.3D numerical model of the seal fluid under different micropore arrangements was developed based on multiphase flow cavitation model in Fluent to study the influence of micropore arrangements on the sealing performance.The leakage rate and the opening force are scored separately.A dualobjective evaluation model based on weighted average method was formulated,which balances the leakage rate and opening force.The arrangements of micropore were optimized at different weight factors for suitable arrangement selection of elliptical micropore under a certain working condition.The results show that the arrangements of micropore have different impacts on the leakage rate and the opening force.The leakage rate is decreased when the number of micropore with 45° orientation angle (Ptype micropore) near the inner diameter is increased.The opening force is the maximal when the number of micropore with -45°orientation angle(Ntype micropore)near the outer diameter is 5,and the number of Ptype micropore near the inner diameter is 5.This arrangement is named as 5N5P.When the leakage rate and opening force are both considered,the arrangements from 5N5P to 0N10P are preferred.At the same time,the number of Ptype micropore near the inner diameter should be decreased when the speed is high or the pressure difference is low,and should be increased when the pressure difference is high or the low leakage rate is desired.