The invention relates to a bolt machining device, in particular to a hexagonal socket flange bolt machining device. The hexagonal socket flange bolt machining device comprises a rack, a heating mechanism is arranged on the rack, a grooved wheel mechanism and a cam mechanism are arranged under the heating mechanism, the rack is provided with a mold mechanism, a thread rolling mechanism, a base andan output mechanism, and the output end of the output mechanism is connected with the input end of the grooved wheel mechanism and the input end of the cam mechanism. A blank material is heated and softened through a heating mechanism, and therefore subsequent punching machining and tapping machining are convenient. In the blank material heating process, the upper portion of the blank material enters the heating mechanism, and rotation of a grooved wheel disc is limited; and the upper portion of the blank material leaves from the heating mechanism under the action of a cam, rotation of the grooved wheel disc is not limited any more, therefore, the grooved wheel disc drives the blank material to fall into the mold mechanism from a second through hole, and subsequent punching machining and tapping machining are convenient. According to the hexagonal socket flange bolt machining device, production equipment in the prior art is integrated, and the production efficiency is improved.