The utility model discloses a needle automatic drawback disposable injector, providing an injector having simple structure, less parts and low cost. The needle automatic drawback disposable comprises a syringe, a push rod and a needle stand assembly which is positioned at the head of the needle tube and which is composed of a needle, a spring, a needle stand and an O-shaped ring. The outer surface of the convex ring on the end of the needle stand and the convex rib on the outer surface of the convex ring on the end of the needle stand are matched with the surface of the inner ring of the O-shaped ring, and surface of the outer ring of the O-shaped ring is matched with the inner surface of the head of the syringe and convex rib on the inner surface of the head of the syringe; after the needle automatic drawback disposable injector is used, the needle tip can not expose, and the withdrawal of the needle is not by the person, so the cross infection caused by the person being punctured by the needle tip can be avoided; the injector is self-destructed and can not be reassembled, so the illegal use can be avoided. The utility model has the advantages of simple structure, less parts, low cost, simple assembly, etc.