Abstract: In order to improve the bioactivity and yield of Auricularia auricula polysaccharides,using Auricularia auricula as raw material,biotransformation was carried out by biological enzyme method. The optimal compound enzyme system was screened by the hypoglycemic functional properties and the polysaccharide yield of Auricularia auricula,and the optimal enzyme conversion conditions were determined by orthogonal test.The Sevag method was used for deproteinization and H₂O₂ was used for decolorization,and the extracted crude polysaccharides of Auricularia auricula were refined.The molecular mass distribution of polysaccharides was analyzed by high performance liquid chromatography,and the hypoglycemic properties of polysaccharides were analyzed and compared by their α-amylase inhibition rate and glucose dialysis delay index.The results showed that:Considering the hypoglycemic functional properties of polysaccharides and the yield of polysaccharides,glucoamylase,papain and pectinase were chosed as enzyme preparations for biotransformation of fungus polysaccharides.The total amount of enzyme added was 700 U/g,and the enzyme ratio was 1:1:1,the ratio of material to liquid 1:60,pH5.0,enzymatic hydrolysis time 1.5 h,enzymatic hydrolysis temperature 50 ℃,the highest inhibition rate of α-amylase was 26.72%,the yield of polysaccharides of fungus was 32.57%. After purification treatment,the color of the black fungus polysaccharide extract changed from brownish yellow to pale yellow,the decolorization rate was 43.15%,and the polysaccharide loss rate was 31.27%. After enzymatic hydrolysis,the polysaccharide was partially degraded,resulting in polysaccharide fragments of different sizes. In addition,the hypoglycemic effect of the enzymatic hydrolysis of auricular polysaccharide was better than that of non-enzymatic hydrolyzed polysaccharide,and its α-amylase inhibition rate was increased by 10.09%;the glucose dialysis delay index was increased by 13.09% at 30 min,and increased by 3.24% at 60 min. The fungus polysaccharide has good blood sugar lowering properties. In this experiment,the biotransformation of Auricularia auricula polysaccharides was carried out by complex enzymatic hydrolysis to improve the biological activity of Auricularia auricula polysaccharides,and provided a theoretical basis for the utilization and clinical application of Auricularia auricula polysaccharides in health care functions.