Dictyophora rubrovalvata is a valuable edible fungus. Its stipe, is rich in polysaccharides, possesses potential biological activity and medicinal value. In this study, we isolated a new polysaccharide, DRP-L, from the stipe of D. rubrovalvata, characterized its structure, and used PC12 to examine its antioxidant effect and mechanism. The results of structural analysis showed that the molecular weight of DRP-L was approximately 2.14 × 10