Through the experiment of preparing stainless steel porous filter by sintering compacted water atomized 0Cr18Ni9 powder in vacuum or pure hydrogen, an empirical formular for the relation between average partical size of the powder and maximum pore size in bubble test is suggested. The effects of different partical size forming pressure and addictives on the porosity, maximum pore size, relative permeability coefficient and tensite strength of the porous stainless steel filter are investegated. The developed filter rings have been put into batch production and obvious economical benefits have been achieved.