结合国内外表面自纳米化的研究成果，综述了表面纳米晶层产生的机理及表面自纳米化对材料表面硬度、摩擦磨损性能、抗疲劳性能以及耐腐蚀性能等的影响，总结了表面纳米晶层的优势，并针对表面纳米晶层性能及单一表面处理技术的不足，详细介绍了金属表面自纳米化与等离子体扩渗、微弧氧化及化学镀等常规表面处理相结合的复合改性技术研究进展，阐明了复合处理技术在材料性能提升上的巨大优势。最后，指出了复合处理技术面临的挑战，并从加强作用机理的研究、复合处理工艺系统性研究以及推进工业化应用等方向着手，提出应充分发挥金属材料表面自纳米化这一普适性的表面处理手段与其他表面改性技术复合的优势。希望为实现金属材料结构功能一体化，促进高性能新型材料和高性能复相表层的研究开发，加快复合改性技术工业化应用的进程提供借鉴与支撑。

Combined with the research results of surface self-nanocrystallization at home and abroad, the generation mechanism of surface self-nanocrystallization layer, effects of self-nanocrystallization on surface hardness, friction and wear property, anti-fatigue property and corrosion resistance were overviewed and advantages and disadvantages of surface self-nanocrystallization were summarized. The latest progress of surface self-nanocrystallization and composite modification technology, which includes some conventional surface treatment methods such as the ion penetration and diffusion, micro-arc oxidation and electroless plating were introduced for the defects of surface nanocrystallization performance and single surface treatment technology. The great advantages of composite treatment technology in improving material properties were expounded. Finally, the challenges of duplex treatment were put forward. Starting from the research of strengthening mechanism, systematic research of composite treatment process and promotion of industrial application, the advantages of self-nanocrystallization of metal surface as the universal surface treatment method and other surface modification technologies are fully brought into play, thus providing reference and support for realizing the structural and functional integration of metal materials, promoting the research and development of high-performance new materials and high-performance composite surface layers, and accelerating the process of industrial application of composite modification technologies.