Abstract: Nano-structure metals always exhibite better mechanical properties compared to their bulk counterparts. The physical and chemical properties of materials are directly determined by their atomic-scale microstructure evolution mechanism. Instigating the atomic-scale deformation mechanism of metallic materials and providing a clear physical picture of their microstructure evolution mechanism at sub-angstrom scale are crucial for the design and optimization of metallic materials with high-performance. The recent progress in scientific research on the deformation mechanism of face-centered cubic (FCC) nano-structure metals was introduced. First, the experimental methods for studying the deformation mechanism of nano-structure metals were introduced. Then, the size effect and deformation mechanism of nanocrystalline and nanocrystal metals were summarized. Finally, the difference of the deformation modes between nano-structure metals and bulk metal materials were summarized briefly, and the challenges and research directions in the future were prospected.