The invention relates to an injection molding processing system for a three-way joint of a plastic pipe. The injection molding processing system comprises a bottom plate, an embracing device, a molding device, a limiting device and an air outlet device, the embracing device is installed at the upper end of the bottom plate, the molding device is fixedly connected to the portion, close to the front side, of the upper end of the embracing device, the limiting device is fixedly connected to the portion, close to the rear side, of the upper end of the embracing device, and the air outlet device is fixedly connected to the middle of the bottom plate. The injection molding processing system can solve the problems that when existing equipment carries out injection molding on a plastic three-way pipe, the equipment cannot be preheated before injection molding, the plastic is prone to solidification in advance during injection molding, the success rate of forming of the three-way pipe is reduced, after injection molding is finished, the plastic cannot be rapidly cooled, the molding efficiency of the three-way pipe is reduced, and meanwhile, the uniformity of plastic distribution cannot be ensured during injection molding, and the phenomenon that the thickness of the pipe wall of the molded three-way pipe is not uniform easily occurs, so that the molding effect of the three-way pipe is reduced, and the like.