The invention discloses a preparation method of auricularia auricula polysaccharide and belongs to the technical field of active ingredient extraction of edible fungi. The preparation method comprises steps as follows: auricularia auricular is smashed, dissolved and subjected to enzymolysis with pectinase, cellulase and alpha-amylase in sequence, then pH is regulated, enzymolysis is performed with neutral protease, ultrasonic treatment is performed after enzymolysis, extraction treatment is performed after ultrasonic treatment, a clear liquid is separated after extraction, and auricularia auricula polysaccharide is obtained after concentration, alcohol precipitation and drying. In consideration of factors such as extraction process cycle, ecological protection, energy consumption, production cost, product activity, process complexity and the like, the preparation method has the advantages of high efficiency, good crushing effect and high yield, and blood lipid reducing activity of extract is greatly enhanced. According to the method for preparing the auricularia auricular extract, the yield is up to 45% or higher, the blood lipid reducing effect of the obtained auricularia auricular polysaccharide is greatly enhanced, various indexes of blood lipid reach significant difference level, (p is smaller than 0.01), and the preparation method is obviously better than existing and conventional preparation methods.