The invention relates to the technical field of molds, in particular to an injection mold automatic thread twisting device. Compared with the prior art, the injection mold automatic thread twisting device uses opening and closing of a mold, a rack installed on a front template drives a gear, then the gear drives a connecting rod and a screw thread core to rotate, so that the screw thread core screws in and screws out along the screw thread shape, during molding, the screw thread core screws in along the screw thread shape so that a screw thread can be molded on the upper side surface of a molding product, after the product is molded, the screw thread core is driven by the gear to screw out along the screw thread shape, then elastic force of a spring is used for separating the screw threadcore from the product, at the same time, a sliding block further moves backwards synchronously, and finally, a mechanical automatic thread disengaging effect is achieved. Full-automatic production ofproducts with screw threads on the side surfaces of molds can be realized, the production efficiency is greatly improved, and moreover, the advantages of safer structure, higher quality yield and thelike are achieved.