Abstract: A motor vehicle aluminum alloy hub having weight reduction sockets at the back cavity includes a wheel disc and a rim; the wheel disc includes a flange, a flange peripheral portion and spokes; the spoke includes a spoke main arm on one side close to the flange, and two spoke branch arms extend from the spoke main arm; the spoke includes a spoke weight reduction socket on one side of the back cavity, and the spoke weight reduction socket is V-shaped; the spokes include five flange peripheral portion weight reduction sockets uniformly distributed around the flange on the back of the flange peripheral portion; and the flange includes flange weight reduction sockets between bolt holes on one side of the back cavity.