Ultrasound-assisted ionic liquid (1-alkyl-3-methylimidazole bromide salt, EADS) was used to extract the polysaccharides of Stropharia rugosoannulata, and the extraction process was optimized by one-factor and response surface method. A DEAE-100 cellulose column and a Sephadex G-100 gel column were used to purify the crude polysaccharide (SRP) of Stropharia rugosoannulata to obtain SRP-I. The structural properties of SRP-I were explored by UV, FTIR, GC-MS, XRD, SEM, EDS, Congo red, thermogravimetric analysis, acid hydrolysis, Smith degradation, and NMR, and the structural properties of SRP-I were evaluated. antioxidant and hypoglycemic activities. The results showed that the optimal extraction process for SRP was 106 min extraction time, 51°C extraction temperature, 4.3 mg/mL EADS mass concentration, 0.52 g cellulase addition, and the extraction rate reached (32.54±0.12)% under these conditions; SRP-I is a neutral polysaccharide with triple helical conformation of α-D-pyran conformation, with a flat and smooth surface, amorphous and crystals coexist, with good thermal stability and a residual carbon rate of 26.34% at 550 °C; the average molecular weight is 24.321 KDa, mainly composed of fucose (53.31 %), glucose (43.32 %) and galactose (3.37 %), where fucose is mainly present in the side chain, while glucose and galactose are more homogeneously distributed in both the main chain and the side chain, and the monosaccharides are mainly distributed among each other in the form of [→3)-Glcp(1→] and [→6)-Galp(1→] structures, while the branched chain structure of [→3,6)-Glcp(1→] also existed; the scavenging rate of SRP-I for DPPH radicals, ABTS radicals, and hydroxyl radicals was up to 82.54%, 51.62%, and 51.57% at the mass concentration of 2.5 mg/mL, respectively, and its The IC50 values were 0.127 mg/mL, 2.438 mg/mL, and 2.446 mg/mL, respectively. α-Amylase and α-glucosidase inhibition rates were 61.2% and 71.4%, respectively, and the IC50 values were 0.97 mg/mL and 0.24 mg/mL.