Non-return device for water treatment

The non-return device for water treatment comprises a drainage pipeline, a protruding pipeline, a water return pipeline and a pressure relief pipeline, a drainage mechanism is arranged in the drainage pipeline, a limiting sealing assembly is arranged in the protruding pipeline, and a water return anti-impact structure is arranged in the water return pipeline. A filter cover cleaning mechanism is arranged in the pressure relief pipeline, the tail of the drainage pipeline is fixedly connected with the end of the protruding pipeline, and the tail of the water return pipeline is fixedly connected with the end of the pressure relief pipeline. According to the non-return device for water treatment, the baffle opening assembly prevents external water from entering the drainage pipeline during water returning, and the impact force on the closed baffle during water returning can be effectively reduced through the arrangement of the water returning anti-impact structure; an annular filter plate, a conical cover plate a