Abstract: In order to ensure the cleanliness of the gas supply system of the space launching station and the normal operation of pipeline instruments, compressors, etc., a filter is installed on the pipeline before the inlet of the equipment. The three-dimensional modeling software Solidworks was used to model the filter under study. The porous medium model in the finite element analysis software Fluent was used for numerical simulation. The mass flow rate of the filter outlet was changed by changing the porosity of the filter and the velocity of the fluid. And the pressure difference between the inlet and outlet is analyzed, and the mass flow rate of the filter outlet is obtained as a function of the inlet velocity when the gas fluid is N₂; the different porosity (0.56 and 0.59) has little effect on the mass flow rate of the filter outlet; the inlet velocity is higher, the inlet and outlet pressure the greater the difference; the larger the porosity, the smaller the pressure difference between the inlet and outlet.