Self-destroying safety injector

The utility model provides a self-destroying safety injector which belongs to the technical field of medical instruments and solves the problems that the existing injector has poor self-destroying capacity and low safety factor. The self-destroying safety injector comprises an injection barrel and an injection pole arranged in the injection barrel, wherein a piston which is sleeved on the injection pole is arranged at the front end of the injection pole, a needle holder is arranged at the front end of the injection barrel, the needle holder is fixedly connected with an injection needle which is communicated with the injection barrel, a needle holder ring that extrudes radially is arranged at the rear end of the needle holder, an axial limit ring is arranged in the injection barrel, the outer diameter of the needle holder ring is larger than the inner diameter of the axial limit ring, the needle holder ring leans against the upper end of the axial limit ring, and a top pressure head which can act on the axial