Nb-Si基超高温合金因兼具高熔点、低密度以及优异的高温强度和蠕变性能，被认为是替代传统镍基高温合金、服务于航空发动机热端构件1200~1400 ℃服役需求的重要候选材料。该类合金通常由铌基固溶体(Nbss)与硅化物构成，其中 Nbss 有利于改善室温韧性，硅化物则赋予材料较高的高温强度和热稳定性。然而，由于脆性硅化物主导的裂纹萌生和扩展、Nbss连续性不足以及高温氧化过程中难以形成稳定保护膜等问题，使Nb-Si基超高温合金面临室温断裂韧性不足与高温抗氧化性能差的瓶颈。本文围绕Nb-Si基超高温合金的制备工艺-组织-性能之间的关系，系统综述了定向凝固、电弧熔炼、粉末冶金和增材制造等制备工艺对其相组成、组织特征与性能的影响，重点归纳了Ti、Zr、Mo、Cr、Al、B、Ta、Hf及稀土元素在组织优化、强韧化和抗氧化性能调控中的作用规律，并进一步总结了多元合金化在抑制Nb₃Si生成、稳定有利硅化物、维持Nbss连续性及形成保护性氧化层方面的协同与负协同效应。最后，针对当前研究中存在的性能评价标准不统一、成分-工艺耦合规律不清及强韧化与抗氧化性能协同设计不足等问题，提出了面向极端服役环境的Nb-Si基超高温合金设计思路与发展方向。

Nb–Si-based ultrahigh-temperature alloys are considered promising candidates to replace conventional Ni-based superalloys in hot-end aerospace components operating at 1200–1400 °C owing to their high melting point, low density, high-temperature strength, and creep resistance. Their microstructures generally comprise a niobium solid solution (Nbss) and silicide phases, with the Nbss providing room-temperature toughness and the silicides imparting high-temperature strength and thermal stability. However, the inherent brittleness of the silicides, insufficient continuity of the Nbss phase, and the difficulty of forming a stable protective oxide scale at elevated temperatures create a long-standing trade-off between room-temperature fracture toughness and high-temperature oxidation resistance, thereby severely limiting the engineering applications of these alloys. This review focuses on the relationships among processing technology, microstructure, and properties in Nb–Si-based alloys. The effects of directional solidification, arc melting, powder metallurgy, and additive manufacturing on phase constitution, microstructural characteristics, and properties are systematically summarized. Particular attention is given to the roles of Ti, Zr, Mo, Cr, Al, B, Ta, Hf, and rare-earth elements in phase stabilization, microstructure optimization, strengthening, toughening, and oxidation resistance. In addition, the synergistic and antagonistic effects of multi-element alloying are discussed in terms of suppressing Nb₃Si formation, stabilizing beneficial silicides, maintaining Nbss continuity, and promoting the formation of protective oxide scales. Finally, current challenges, including the lack of unified performance evaluation criteria, insufficient understanding of composition–process coupling, and limited design strategies for simultaneously enhancing toughness and oxidation resistance, are highlighted. Future directions for the design and development of high-performance Nb–Si based ultrahigh-temperature alloys for extreme service environments are also proposed.