Micro and nano copper powders, mainly on nano and sub-micron scales, are critical functional materials in the modern military, shipbuilding, aerospace, and cutting-edge science and technology fields due to their high electrical and thermal conductivity, low electrochemical mobility behavior, strong solderability, low price and easy availability of raw materials. For different applications, there are different requirements for the morphology, particle size, and surface properties of copper nanopowders, while smaller particle size distribution and higher activity, as well as easy oxidization, put forward higher requirements for the preparation and storage. Liquid-phase reduction method utilizes the mechanism of redox reaction to control the particle size and morphology of copper nanopowders by regulating the process conditions. On this basis, surface modification treatment can be carried out to improve the antioxidant ability to achieve better application characteristics. In this paper, the effects of different regulating factors (reducing agent, copper source, protective agent, solvent, reaction temperature, and pH) on the morphology, particle size, and dispersion of copper nanopowders in the liquid phase reduction process are reviewed, and the three treatments of copper nanopowders for antioxidant resistance (surface capping, surface crystal reconstruction, and surface transformation treatment) are further summarized, as well as the current status of the application of copper nanopowders in the fields of chemical catalysis, medical antimicrobial, lubrication friction and electronic pastes. The current status of the application of copper nanopowders in chemical catalysis, medical antimicrobials, lubricating friction, and electronic pastes is briefly described. The application dilemma and development direction of copper nanopowders are summarized. The development prospect is outlooked, to provide a reference for the development of copper nanopowders prepared by liquid phase reduction method.