SiCp/Al是航天大型装备结构件轻量化制造的重要材料之一，但其多相异质特性导致加工损伤严重、表面质量难以控制。本研究通过-196 ~ 20 ℃宽温域拉伸试验，揭示了SiCp/Al材料低温强化效应主导的力学性能演化规律；开展了超低温与常温铣削实验研究，分析了材料低温特性与工艺参数对铣削力和表面形貌的宏微观作用机制。研究结果表明，超低温环境中材料屈服强度和抗拉强度更大，并且液氮冷却介质降低了切削温度，使局部热软化效应减弱，因此铣削力较常温铣削更大。但由于超低温冷却下材料界面强度也有所提高，减小了铣削表面的凹坑和裂纹损伤程度，所以表面粗糙度较常温加工更好。研究成果为航天难加工复合材料精密制造提供了新的理论基础与工程依据。

SiCp/Al is one of the critical materials for lightweight manufacturing of large aerospace structural components. However, its multi-phase heterogeneous characteristics lead to severe machining damage and challenges in surface quality control. This study conducts tensile tests across a wide temperature range from -196 to 20°C, revealing the evolution of mechanical properties dominated by cryogenic strengthening effects in SiCp/Al materials. Comparative experimental studies on cryogenic and room-temperature milling are performed to analyze the macro-micro mechanisms of material cryogenic characteristics and process parameters on cutting forces and surface integrity. The results demonstrate that the material exhibits higher yield strength and tensile strength in cryogenic environments, while liquid nitrogen cooling reduces cutting temperature and weakens local thermal softening effects, resulting in greater milling forces compared to room-temperature machining. However, as the cryogenic cooling enhances the interfacial strength of the material, it reduces the extent of surface pits and crack damage during milling, producing better surface roughness than conventional processing. This research provides a novel theoretical foundation and engineering basis for precision manufacturing of difficult-to-machine aerospace composites.