An optical lens injection molding module is presented, wherein the molding module has a mold core made by a metal 3D printer. The metal 3D printer first lays metal powder on a platform and then transmits laser heat energy for irradiation sintering to melt the metal powder together into a predetermined shape as a metal layer, and by repeated formation of a plurality of metal layers. The mold core has a top surface, a bottom surface, a peripheral wall, a through aperture, a plurality of mold cavities, and at least one temperature controlled flow channel. The mold cavities and the temperature controlled flow channel are disposed in the mold core. The through aperture is disposed at a center of a circular position of all the mold cavities, penetrates both of the top surface and the bottom surface, and connects radially to each mold cavity via a plurality of guiding grooves.