An exhausting device of a low-pressure aluminum alloy wheel casting mold, which includes a control mainframe, a connecting line, a gas storage station, a ventilating pipeline, gas inlet plugs, an exhausting plug and the like, the control mainframe is connected with the gas storage station through the connecting line, and the gas storage station is connected with the gas inlet plugs through the ventilating pipeline; the gas inlet plugs are arranged at the bottom mold window; the mold filling process of the high-temperature molten aluminum can be completed in a relatively oxygen-free environment, direct contact between the molten aluminum and oxygen is avoided, and the occurrence probability of the oxidation slag inclusion defect in the wheel casting process is effectively controlled, so that the internal quality of the casting is remarkably improved.