<p>Sand mold additive manufacturing forming technology has the advantage of not being limited by the complexity of castings and has been widely applied in the precise manufacturing and forming of complex castings for high-end equipment such as aerospace. It also has significant advantages in the innovative development, manufacturing, and application verification of single-piece and small-batch products. This paper innovatively proposes a composite process of additive manufacturing and low-temperature treatment for sand molds, which refers to the rapid low-temperature treatment of additive manufacturing resin sand molds in a low-temperature sub-zero environment to obtain pre-cooled sand molds, so that the sand molds have a specific low-temperature subcooling degree before the high-temperature molten metal is poured. The research adopted inkjet additive manufacturing technology to manufacture the sand mold of the thin-walled cabin casting of A356 aluminum alloy. The filling behavior and solidification process of the molten metal in the low-temperature-treated sand mold and the common sand mold casting process were compared and analyzed, and the macro- and micro-properties of the alloy under the two sand mold casting processes were compared and analyzed. The research results show that the heat transfer capacity and solidification rate of low-temperature-treated sand molds are superior to those of common sand molds. They can significantly enhance the mechanical properties and elongation of castings, refine the casting structure, improve the elemental distribution state, and achieve high-performance manufacturing of thin-walled castings, providing a technical foundation for the precise manufacturing of high-quality castings in aerospace.</p>