When water runs through the water inlet into the filter cartridge, the impurities were intercepted on the inner wall of the filter cartridge, and the clean water flows out of the outlet. As the impurities in the inner surface of the filter tube piles up, the differential pressure between the inlet and outlet runs up to the pre-set value, the self-cleaning process will begin. The self-cleaning process can also begin when it reaches the washing time or manual prefabrication. And it includes two steps: Open the automatic drain valve on the filter；The cleaning brush inside the filter mesh is drove by the motor, and the impurities stopped by the filter mesh will be discharged from the drain valve. When cleaning, the system does not cut off; the whole operation process of the filter is controlled by an intelligent control box which is equipped with the filter. Control mode consists of differential pressure, time, manual and PLC control.