The invention discloses a double-layered ring part inward flanging die and a flanging technology. The double-layered ring part inward flanging die comprises a lower template, an upper template, a die shank, a fixing plate, a pressing block, a pressing plate, a concave die, a positioning block, a lower cushion plate, a spring, a stop collar, a shock absorber, a guide pillar, a convex die, a guide sleeve, an upper cushion plate, and a small guide pillar, wherein the die shank is connected with the upper template through four screws; the die is connected with a punching machine through the die shank; the pressing plate is connected with the concave die through a screw; the positioning block is accommodated in a cavity of the concave die; the guide sleeve is tightly matched with the upper template; the guide pillar is tightly matched with the lower template. The flanging technology of the double-layered ring part inward flanging die is completed on an overhanging press with 800 KN and comprises the following steps: aligning the upper template with the lower template, clamping the upper template and the lower template on an upper platform and a lower platform, sleeving the part on the equipment, raising up the upper template, rebounding the convex die under the action of the shock absorber, and stepping aside the flanging part of the ring part. The double-layered ring part inward flanging die and the flanging technology disclosed by the invention have the advantages that the inner side flanging of the double-layered ring part can be implemented, the production efficiency can be greatly improved, the machining size of the part can be ensured, and the good effect can be achieved.