The stainless steel filter is composed of a shell, a multi-element filter element, a backwashing mechanism, a differential pressure controller, etc. after that, the inner cavity of the stainless steel filter is divided into upper and lower cavities by the diaphragm in the shell. The upper cavity is equipped with multiple filter elements, which makes full use of the filtering space and significantly reduces the volume of the filter. A backwashing suction cup is installed in the lower cavity. During operation, the turbid liquid enters the lower chamber of the filter through the inlet and the inner chamber of the filter element through the diaphragm hole. Impurities larger than the filter element gap are intercepted, and the purified liquid passes through the gap to the upper chamber and is finally sent out from the outlet.