Corrosion preventing device used for inner pipe wall of water filling pipe

The invention discloses a corrosion preventing device used for an inner pipe wall of a water filling pipe. The corrosion preventing device comprises a tank body with a flange plate in the middle as well as a water inlet pipeline and the water filling pipe, wherein a partition plate and a sealing plate are arranged on the inner wall at one side of the tank body in a spaced manner; a plurality of second sacrificial anodes are mounted on the inner wall at the other side of the tank body; the two ends of a sleeve separately penetrate through the partition plate and the sealing plate; the sleeve is opposite to the water inlet pipeline; a sealed ring cavity is formed between the sleeve and the tank body; a plurality of first sacrificial anodes are fixedly arranged in the ring cavity; a plurality of water transmission holes communicating with the ring cavity are formed in the partition plate; and the outer wall of one end, close to the sealing plate, of the sleeve is provided with a plurality of communicating holes