The invention discloses an efficient long-range firearm barrel capable of achieving hidden stretching. The efficient long-range firearm barrel comprises a body and accessories. The body comprises a front barrel body, a front sliding clamp, a middle barrel body, a middle sliding groove, a middle sliding clamp, a rear barrel body and a rear sliding groove, and the accessories comprise a front protruding edge, a front buffer pad, a middle clamping pad, a middle buffer pad, a rear clamping pad and a rear protruding edge. . The front barrel body is arranged on the inner side of the middle barrel body, and the front sliding clamp is symmetrically arranged on the outer side of a rear end opening of the front barrel body in a protruding manner; the middle barrel body is arranged on the inner side of the rear barrel body, and the middle sliding groove is symmetrically formed in the inner side wall of the middle barrel body; the middle sliding clamp is symmetrically arranged on the outside of a rear end opening of the middle barrel body in a protruding manner, and the rear barrel body is arranged on the outer side of the middle barrel body; the rear sliding groove is symmetrically formed in the inner side wall of the rear barrel body, and the front protruding edge is arranged on the outer edge of a front end opening of the front barrel body; the front buffer pad is arranged on the rear side of the front sliding clamp, and the middle clamping pad is arranged at the rear end of the middle sliding groove; the middle buffer pad is arranged on the rear side of the middle sliding clamp, and the rear clamping pad is arranged at the rear end of the rear sliding groove; and the rear protruding edge is arranged on the outer edge of a rear end opening of the rear barrel body, and all the clamping pads and buffer pads are comprehensively and specially synthesized through a high temperature and abrasion resisting nano material with magnetism and a high-energy metal material.