Injection pen capable of being automatically driven

The invention relates to the technical field of medical instruments, and provides an automatically-driven injection pen which comprises a shell, an accommodating cavity and a medicine cavity which are formed in the axial direction of the shell and communicate with each other are formed in the shell, and a first limiting part and a second limiting part are arranged in the accommodating cavity; the adjusting mechanism is rotatably arranged in the containing cavity, and the adjusting mechanism is provided with an adjusting station and an injection station in the axial direction of the containing cavity; two ends of the torsion spring are respectively connected with the adjusting mechanism and the shell; the injection mechanism is arranged in the containing cavity and the medicine cavity, a threaded rod arranged in the axial direction of the containing cavity is formed at one end of the injection mechanism, and the other end of the injection mechanism is connected with the shell. Through improvement of a transmis