The invention discloses an atlantoaxial lateral mass joint fusion cage which comprises a main body, a front development needle and a rear development needle, wherein the main body comprises a rectangular front wall and a circular arc wall, and two parallel opposite sides of the rectangular front wall are connected respectively with two lateral sides of the circular arc wall; the outer surface of the front wall is an indented plane, the inner surface of the front wall is an inward bulging plane, and a threaded through-hole is formed in the front wall; the front development needle is located on the left side of the front wall, is exposed on the surface, and runs through the main body longitudinally; and the rear development needle is located in the center of the circular arc wall, is exposed on the surface, and runs through the main body transversely. The atlantoaxial lateral mass joint fusion cage is used for implanting an atlantoaxial lateral mass joint space, and has the functions of supporting a normal height of the joint space, maintaining a normal physiological axis, embosoming filling and implantation of a bone graft, stabilizing the joint, and promoting lateral mass joint fusion; the technical problem that when fixing fusion is required caused by atlantoaxial dislocation or instability, the prior art cannot control the intervertebral space height, the physiological axis and the stability effectively is solved; and the fixed bone graft fusion is more normalized, and the effect is better.