Abstract: Additive Manufacturing (AM) technology, with its layer-by-layer deposition principle, has broken through the geometric constraints and material utilization bottlenecks of traditional manufacturing processes, becoming a core supporting technology in the aviation sector for lightweight design, functional integrated manufacturing, and supply chain optimization. This paper systematically reviews the current applications of metal additive manufacturing and composite additive manufacturing in key areas such as aircraft engines, fuselage structures, and spacecraft components, focusing on the technical characteristics and applicable scenarios of mainstream processes like laser powder bed fusion (LPBF), electron beam melting (EBM), and directed energy deposition (DED). It delves into the process-performance correlation mechanisms of titanium alloys, nickel-based superalloys, refractory metals, and novel composite materials. The certification standards and regulatory frameworks of international organizations such as the FAA, EASA, and SAE are also summarized. By analyzing engineering practice cases from companies like GE Aviation, Airbus, and Boeing, the technical and economic advantages of additive manufacturing in weight reduction, cost savings, and shortened delivery cycles are quantitatively evaluated. Finally, addressing industry pain points such as process stability control, permissible material values, and lifecycle cost optimization, a development path of "material-process-design-performance" collaborative optimization is proposed, along with future directions such as intelligent monitoring, hybrid manufacturing, and ultra-high-temperature material forming.