Abstract: The relation between the sizes of inclusions filtered, pore sizes of materials and the accuracy of filtering has been described by analysing the filtering mechanics of sintered bronze filtering materials and comparing actuxal with test. The key parameters capable of resulting in the ineffectiveness of filtering system-permeability factors and their detail methods of applications engineering have been discussed, Other problems concerned by disigners, such as material standard, oxidation resistance etc.and the structure and process technology of products have also been given out.