A upstream pumping mechanical seal with a slant groove was proposed.The experimental scheme of upstream pumping mechanical seal was designed by orthogonal test method,and the effect of each test parameter on the opening force and leakage of the sealing end face was analyzed by the numerical simulation of Fluent software.The results show that within the range of test parameters,the factors that have a significant influence on the opening force of the end face are the groove number,the angle of radial direction,the groove depth,the liquid film thickness in nongroove area,the rotational speed and pressure difference.The opening force is increased with the increasing of the angle of radial direction,the groove depth,the liquid film thickness in nongroove area,the rotational speed and pressure difference,and decreased with the increasing of the groove number.The factors that have a significant influence on the leakage are the groove depth,the groove width ratio,the liquid film thickness in nongroove area,the rotation speed and pressure difference.The leakage is increased with the increasing of the groove width ratio,the liquid film thickness in nongroove area,the rotation speed and pressure difference,and decreased with the increasing of the groove number.According to the results of orthogonal test,the preliminary optimized structural parameters were proposed.