Abstract: Natural polysaccharides and polyphenols are widely present in various plants and have various important biological pharmacological activities. The composite structure formed by covalently bonding polyphenols with natural polysaccharides can effectively improve their physicochemical and functional properties. The free radical grafting method has the advantages of being environmentally friendly and easy to operate compared to chemical coupling methods and enzyme mediated methods. In this review, we focus on the characterization methods, health functions, and potential applications of polysaccharide and polyphenol graft copolymers mediated by free radicals, in order to provide theoretical references for better design of such complexes and their applications in the food industry, healthcare, and other fields in the future.