Abstract:Polyphenols are important secondary metabolites in plants and have strong antioxidative properties.These compounds play a valuable role in the prevention of chronic conditions such as cardiovascular diseases.As antioxidants，plant polyphenols can be used in a variety of food-related，medical，and other sectors.The application of nanotechnology to protect polyphenols from degradation and to improve their stability and antioxidant activity has been of great significance for the food industry.In the paper，the technologies for the extraction，separation，and purification of polyphenols and their functional properties are discussed in detail，which provides a reference for the preparation and application of polyphenol nanoparticles.