Method for preparing lycium ruthenicum polysaccharide

The invention relates to a method for extracting and preparing lycium ruthenicum polysaccharide, which solves the problems of the existing method that the raw material cannot be sufficiently utilized, the cost is high, the yield of polysaccharide is low and the activity is poor. The method comprises the following steps of in the preparation process, adopting an ultra-fine crushing technique, crushing the lycium ruthenicum residues with pigment extracted, then degreasing to obtain the degreased lycium ruthenicum powder, enzymatically decomposing the degreased powder, adopting a freezing and thawing technique to repetitively freeze and thaw for 3 to 7 times, and finally carrying out filtering, alcohol deposition, deproteinization treatment, freeze-drying and the like, so as to obtain the lycium ruthenicum polysaccharide finished product with anti-oxidative activity. The method has the advantage that the lycium ruthenicum residues with pigment extracted are used as the raw material, and the ultra-fine crushing t