The utility model discloses a last top surface inclination that a groove was carved on with to medial surface inclination that circle inserted forging die fastening device belongs to the inserted forging die field, and its structure includes upper die base, die holder, go up insert die and insert die down, goes up the insert die and carves on through and fix in the upper die base with the top board, and lower insert die is carved under through and is fixed in the die holder with the holding down plate, and the adjacent side with the top board groove in upper portion that goes up the insert die is provided with carves a groove carves on, and carve an inslot through the top board dress on last insert die carved on, unanimously, down the lower part of insert die is provided with down and carves a groove with pushing down the adjacent side of card slot, carve down by the holding down plate dress at the lower inslot of carving of insert die down, the medial surface inclination of carving down and lower bottom surface inclination of carving a groove are unanimously. The utility model discloses has loading and unloading convenient and fast, safe and reliable, low in labor strength, go up insert die, lower insert die fastening reliably, excellent in use effect, upper die base, the die holder processing degree of difficulty are little, processing is simple, and convenient operation compresses tightly characteristics such as effectual.