The preparation methods of Cu nanoparticles are reviewed, which include mechanical ball milling method, radiation synthesis, physical vapor deposition and chemical method. The key issues of anti-oxidation, low temperature sintering and conductivity improvement of nano-copper conductive ink are discussed. The applications of Cu ink in RFID tags, membrane switches and touch screens are concluded. The research direction of nano-copper conductive ink is put forward as that of anti-oxidation, low temperature sintering, a variety of printing methods and product applications.