The invention relates to a forged rolling ring assembling form applicable to an aging drum and a processing method thereof. The forged rolling ring assembling form comprises a drum body, a rolling ring and a rolling ring mounting seat, wherein the outer circle of the thickened part of the drum body is provided with two circles of ring ribs; the rolling ring mounting seat is fixedly arranged on the ring ribs; two circles of reinforcing ribs are welded and arranged among the rolling ring mounting seat, the ring ribs and the outer circle of the drum body; the rolling ring is of a ring forged structure and is fixedly arranged on the rolling ring mounting seat; two ends of the inner circular surface of the rolling ring are respectively machined with a groove by turning; one end of the two ends of the rolling ring is machined with a boss matching with the groove by turning, and the other end of the two ends of the rolling ring is machined with a step with same length and different depth with the groove by turning; the rolling ring mounting seat and the rolling ring are assembled to form an edge-aligned counter bore; the position of the counter bore is bonded with a circle of press plates by pieces; and the press plates and the rolling ring mounting seat are fixed through bolts. According to the invention, the rigidities of the forged rolling ring assembling form and the drum body can be reinforced, so smooth and stable operation of equipment all the year round is realized; meanwhile, a conventional casted rolling ring can be perfectly replaced, so the forged rolling ring assembling form has reinforced quality and prolonged service life.