A mold for reducing defects in low pressure casting of an aluminum alloy wheel includes a top mold, a side mold and a bottom mold, wherein the top mold is arranged above the bottom mold to mold a back cavity of a wheel, the bottom mold is arranged below the top mold to mold a front wheel disc of the wheel, the side mold is arranged on the side of the top mold and the bottom mold, and the top mold, the side mold and the bottom mold collectively surround a casting cavity of the aluminum alloy wheel, wherein the upper surface of the bottom mold includes a recessed portion configured to form a spoke and a boss portion configured to form a window and wherein the boss portion configured to form the window includes cooling ducts.