An aluminum alloy hub lathe fixture, which includes a main plate, a mounting seat, a hydraulic power clamping head, a pull rod, a sliding seat, a connecting pin, a fan-shaped clamping jaw, a sealing cover, a deflection block, a deflection shaft, a centrifugal force balance block, a centrifugal mechanism base, a spring and screws, wherein the main plate and the mounting seat are connected together through screws, so that a housing of the entire fixture is formed; the hydraulic power clamping head is fixed on the mounting seat through screws; one end of the pull rod is mounted on the hydraulic power clamping head through screws, and the other end of the pull rod is connected with the sliding seat through the connecting pin; the fan-shaped clamping jaw is fixed on the sliding seat through screws.