In the building construction, the leakage phenomenon of the sewer inlets of toilets, kitchens, etc. is common. In order to prevent the leakage, the utility model designs an anti-leakage cover for a sewer inlet. The utility model is composed of a protective wall and a protective brim connected with one end of the protective wall. The external profile diameter of the protective brim is bigger than the diameter of a preformed hole. The anti-leakage cover for a sewer inlet is arranged at the intersection of the sewer line and the ground, which stops the leakage happening.