Extraction method and application of phlebopus portentosus polysaccharide

The invention relates to an extraction method and application of phlebopus portentosus polysaccharide. The method comprises the following steps: S1, adding ethanol having a concentration of 95% into phlebopus portentosus sporocarp powder, carrying out ultrasonic dispersion, standing at room temperature, and reserving a precipitate 1; S2, adding water, extracting in a water bath, and concentrating; S3, adding ethanol having a concentration of 95% under magnetic stirring for precipitation, standing at low temperature, and centrifuging to obtain a precipitate 2; S4, extracting by using a Sevage reagent, and taking supernate; S5, adding SP-825 macroporous resin, and decolorizing; S6, adding ethanol having a concentration of 95% for precipitation, standing at low temperature, and centrifuging to obtain a precipitate 3; S7, eluting through distilled water and NaCl solutions with different concentrations in DEAE-52 fiber column chromatography, ; S8, concentrating, dialyzing and drying. The phlebopus portentosus poly