The aim of this study was to conduct a comprehensive analysis of the relationship between the fingerprint of Tremella fuciformis polysaccharides (TFPs) sourced from China and their bioactivities, with an emphasis on identifying the most bioactive TFP variety that significantly mitigated radiation-induced intestinal injury (RIII). Firstly, the multi-fingerprints we developed indicated that TFPs were classified as acidic, primarily consisting of mannose, rhamnose, glucuronic acid, glucose, xylose, and fucose, with average molecular weight (Mw) ranging from 1.65 × 10