The utility model discloses a half-thread screw with a female hole dodecagonal flange head. The half-thread screw comprises a screw body. The screw body has a rod part body and a tail end part body, which are integrally molded, wherein an external thread body with continuous outside recessed convex tooth-socket structure is axially fabricated at the head end of the rod part body, and the thread axial length of the external thread body is at most equal to two thirds of the length of the rod part body; an internal thread body with continuous inside recessed convex tooth-socket female hole structure is axially fabricated at the tail end of the screw body, and the length of the internal thread body is at least equal to the length of the tail end part body; and the screw body is a dodecagonal third structural body. An inwardly-recessed threaded hole is formed at the tail part and has novel structure and convenient fabrication, and the aperture of the inwardly-recessed threaded hole is moderate, so that the half-thread screw maintains the performance of the original screw and is added with the novel rear-part output connection mode without affecting the structural strength of the original screw. The screw thread of the threaded hole is processed in different specifications so as to meet the requirements for different connection modes, for example, metric screw thread, inch screw thread, U.S. standard screw thread and the like.