The invention discloses a machining technique for a sprue bush provided with a water delivery ring. The machining technique for the sprue bush provided with the water delivery ring comprises the following steps that (1) the water delivery ring is prepared and turned into a ring body, at least two water delivery grooves are circumferentially formed in the inner wall of the ring body and communicate, and through holes penetrating through the wall surface of the ring body are formed; (2) a sprue bush body is prepared, and the diameter of the periphery of the small end of the sprue bush body is larger than the diameter of the inner wall of the water delivery ring; and (3) the water delivery ring is heated to increase the inner diameter of the water delivery ring, the water delivery ring is vertically and naturally placed corresponding to the periphery of the small end of the sprue bush body and naturally cooled to the room temperature, and then the water delivery ring is tightly sleeved with the sprue bush body. According to the machining technique for the sprue bush provided with the water delivery ring, a combined structure is adopted, the water delivery grooves are directly machined and formed in the inner wall of the water delivery ring, and the machining technique is simple; and a heating and interference fit assembling way is adopted so that the water delivery grooves can be firmly fixed to the sprue bush body, the sealing effect is good, water leakage is avoided, and an extremely good cooling effect can be achieved.