石墨烯是石墨的基本结构组成单元，是由碳原子以sp2杂化轨道组成、呈六角型蜂巢状且具有独特二维结构的纳米材料。由于其优异的机械及润滑特性，成为近年来国内外摩擦学领域研究的聚点和热点。大量研究表明：石墨烯不仅在微纳接触尺度下展现出超润滑性能，而且在宏观接触方式下也展现出非凡的摩擦学特性。详细介绍了石墨烯在微观接触和宏观接触状态下摩擦学性能的影响因素。在微观接触状态下，滑动发生在完美、平滑的基础面晶面上，施加的载荷小，接触面小，其摩擦学性能主要受到结构形变、表面清洁（包括缺陷、环境、化学官能团）、公度/非公度结构等因素影响。在宏观接触状态下，施加的载荷大，接触面积大，影响因素众多，除了上述在微观接触状态时提到的影响因素，还涉及材料本身存在的各向异性、晶界以及宏观力的破坏等作用，受到棱边键及摩擦引起的悬键暴露和定序摩擦界面的形成的影响。基于此，分析了石墨烯获得不同尺度超低摩擦所需的必要条件和润滑机制，展望了石墨烯摩擦学研究未来发展方向和仍需解决的问题。

As the basic structural unit of graphite, graphene is a unique two-dimensional nanostructure composed of sp2 hybridized orbitals of carbon atoms in hexagonal honeycomb crystal. It has become the focus of tribology research at home and abroad in recent years due to its excellent mechanical and lubricating properties. Graphene not only has achieved the superlubricity at nanometre-scale and micrometer-scale contacts, but also shows extraordinary tribological properties at macroscopic contacts. The influencing factors of graphene tribological properties at micro-contact and macro-contact states were introduced in detail. At micro-contact state, the sliding occurred on the perfect and smooth crystal surface and the contact force and contact area were small, so the tribology performance of graphene was mainly subject to structural deformation, surface cleanliness including defects, atmosphere and chemical functional groups and commensurate/incommensurate structure. At macro-contact state, contact force and contact area were large, so tribological properties were influenced by many factors. In addition to the influencing factors at micro-contact states, the anisotropy of the material, the grain boundary and the destruction of macroscopic forces were also involved and the graphene was also affected by edge bonds, friction-induced dangling bonds exposed and ordered lamellar structure on the sliding interface. On this basis, the necessary conditions and lubricating mechanism of graphene to obtain ultra-low friction at different scales were further analyzed, and the future development direction and problems to be solved in tribological research of graphene were prospected.