Due to its nanoscale, nano-metal powder has significant surface effect, small size effect, quantum size effect and macroscopic quantum tunneling effect, which make nano-metal powder show many unique advantages in performance, such as higher strength, hardness, toughness, catalytic activity and electrical conductivity. Not only in magnetism, optics, electricity, acoustics, thermodynamics, mechanics, and chemistry and other fields present a new type of functional properties, but also uniquely demonstrated non-macroscopic objects as well as single-atom specific properties.