The invention discloses the technical field of an injection mold, in particular to a mold mechanism for realizing automatic falling of an injection molded part. The mold mechanism for realizing the automatic falling of the injection molded part comprises a base and columns arranged at the left and right sides of the upper surface of the base, the upper ends of the columns are provided with installing brackets, drive cylinders are longitudinally installed in the middles of installing brackets, upper mold bases are installed at the bottoms of the output ends of the drive cylinders, a lower moldbase is arranged in the inner cavity of the base, a thread supporting plate is screwed at the lower side of the inner cavity of the base; supporting plates are arranged on the two side walls of the lower mold base; the upper sides of the supporting plates are connected with pulling rods extending to the upper side of the base; through the cooperation effect of the pulling rods and the supporting plates, the drive cylinder can pull the lower mold base when driving the upper mold base to move upwards and open mold, so the step of taking out the injection molded part is reduced; the processing efficiency is improved by reducing the design of steps; through arranging a feeding switch mechanism, the self-injection action can be carried out during the mold closing process, and the degree of automation is high.