Sewer pipe fitting

The utility model provides a sewer pipe fitting, and belongs to the technical field of sewer pipe materials. The technical problem that according to an existing drainage piece, water leakage is prone to occurring due to a water tank overflow hole is solved. The sewer pipe fitting comprises an inner pipe and an outer pipe arranged on the outer wall of the inner pipe in a sleeving mode, a first water inlet used for being connected with the bottom of a water tank is formed in the upper end of the inner pipe, a side cavity communicated with an overflow hole is formed between the inner wall of the outer pipe and the outer wall of the inner pipe, and the upper edge of the outer pipe and the upper edge of the inner pipe form a second water inlet communicated with the side cavity. A first water outlet is formed in the lower end of the inner pipe, a second water outlet communicated with the side cavity is formed in the bottom of the outer pipe, and the first water outlet is communicated with the second water outlet. T