Abstract: Copper nanowires not only have excellent electrical conductivity comparable to silver, but also have good light transmittance and flexural resistance due to the size effect at the nanoscale. In addition, it is far cheaper than gold and silver, hence it is an ideal electrode material for preparing flexible electronic devices. The synthesis methods of copper nanowires were systematically reviewed, such as template method, vapor deposition method, electrospinning technology, and chemical liquid phase method. Purification technologies based on water-hydrophobic organic solvent system and acid treatment for copper nanowires were introduced. Various cladding materials with core-shell structure and corresponding cladding technologies used to improve the oxidation resistance and stability of copper nanowires were listed, including inert metals, carbon-based materials, and organic polymer materials. The application status of flexible electronic devices integrating high-quality copper nanowires (or their composites) with flexible substrates (paper-based, polyurethane, and polyethylene terephthalate, etc.) in the fields of flexible transparent electrodes, energy storage/conversion, and flexible sensors were concluded. Finally, the challenges faced in practical application were prospected.