The invention discloses a low-pressure casting secondary pressurization technology for a wheel. According to the technology, the characteristics of stable low-pressure mold filling of molten aluminumalloy and rapid solidification of a rim are reserved, a sprue spreader and the molten aluminum alloy at a center sprue are frozen in a forced water cooling mode, a mold cavity is sealed, a center extrusion rod moves downwards to carry out secondary pressurization on the aluminum wheel, and therefore the mechanical properties of materials of aluminum wheel castings and the production efficiency ofa casting technology can be improved.