The invention discloses a special aluminum casting joint for an aluminum alloy vehicle body frame. The aluminum casting joint comprises a first connecting part, a plurality of second connecting parts,and a plurality of limiting steps, wherein the first connecting part is cylindrical, and one end of the first connecting part is provided with a first connecting groove in the axial direction; the plurality of second connecting parts are cylindrical, the plurality of second connecting parts are arranged around the other end of the first connecting part, one ends of the plurality of second connecting parts are fixedly connected with the first connecting part, the other ends of the second connecting parts are provided with second connecting grooves in the axial direction, and the second connecting grooves communicate with the first connecting groove; the limiting steps are fixedly arranged in the first connecting groove and the second connecting grooves correspondingly; and the aluminum casting joint is of an integral forming structure. According to the special aluminum casting joint for the aluminum alloy vehicle body frame, the effective connection of different angles of an aluminum alloy profile and sections of different profiles can be achieved, the integral rigidity and the integral strength of the joint part are ensured, the welding length is reduced, and the production efficiency is improved.