The invention discloses a combined waterproof sleeve for a toilet. The sleeve comprises a base, the edge of the lower end of the side wall of the base is outwards provided with a water stop wing ring,the interior of the base is hollow, the upper end and the lower end of the base are both communicated with the outside, the lower end of the base is inwards flanged to form a fixing ring, a sleeve cover plate is placed at the upper end of the fixing ring, and at least two mounting holes allowing a pipeline to penetrate through are formed in the sleeve cover plate. After the base is poured into afloor, the sleeve cover plate is placed on the upper end face of the fixing ring in the base, the pipelines are connected with the mounting holes in the sleeve cover plate respectively, and thereforemounting of the multiple pipelines is completed, and time and labor are saved.