Injection device

The utility model relates to the technical field of medical instruments, and provides an injection device which comprises a containing part and an injection part, the containing part is used for containing medicine, and the injection part comprises a first pipe body, a pipe body assembly, a limiting ring and a first limiting piece; the pipe body assembly is in threaded connection with the first pipe body; the outer wall of the limiting ring is clamped with the inner wall of the pipe body assembly; the first limiting piece is in threaded connection with the limiting ring, when the tube body assembly is screwed out relative to the first tube body, the limiting ring can axially move relative to the first limiting piece so as to memorize the adjusting amount of the medicament, and a first stop block is arranged at one end of the first limiting piece and used for limiting screwing-out of the limiting ring. According to the injection device, by arranging the limiting ring, the first limiting piece and the first sto