Self-cleaning filter

The invention belongs to the technical field of water treatment, and relates to a self-cleaning filter. The self-cleaning filter comprises three filter chambers (10, 20, 30) connected in parallel, three filter elements (11, 21, 31) which are respectively positioned in the three filter chambers, a water inlet pipe (3) for inputting pretreated materials, a switch valve (2) which is positioned between the water inlet pipe and the filter chambers and is provided with four pipes (b1, b2, b3, e), a water outlet pipe (4) which is connected with the filter chambers and is used for outputting filter liquor, a waste liquid pipe (5) connected with the pipe (e), and a pressure monitoring and alarm system (6) connected with the switch valve (2). The self-cleaning filter has the beneficial effects of realizing functions such as self-cleaning, continuous filtering, intermittent back-washing and full-automatic operation, reducing the operating strength of workers and improving the operating efficiency, thus having broad appl