Abstract: Food packaging is an important field of food research, which plays an important role in maintaining food quality. As an important active substance, polysaccharides are often used as biopolymer materials to produce edible films to reduce the pollution of traditional plastic packaging due to their natural non-toxic, biodegradable and selective permeability to carbon dioxide and oxygen. In order to further develop and apply polysaccharide based edible films, this article summarizes the composition of polysaccharide based natural polymers, the characteristics of polysaccharide based films and their applications in food preservation, and looks forward to their development prospects, in ordor to providing a theoretical basis for the development and industrial application of polysaccharide based films in fresh-keeping technology.