The filter consists of a housing, a multi-element filter, a backwashing mechanism, and a differential pressure controller. The diaphragm in the housing divides the inner cavity into upper and lower chambers. The upper chamber is equipped with a plurality of filter cores, which fully filters the space and significantly reduces the volume of the filter. The back chamber is equipped with back flushing. Suction cups. . The filter adopts a high-strength wedge filter and automatically cleans the filter element through differential pressure control and timing control.