The present invention discloses a preservation method of mushrooms. The preservation method of the mushrooms comprises the following steps: chitosan is added to an acrylic acid aqueous solution to bestirred evenly; vinylpyrrolidone and ceric sulfate are added under nitrogen; reaction is conducted; 1-ethyl-(3-dimethylamino propyl) carbodiimide hydrochloride is added; the materials are stirred; L-cysteine is added; the reaction is conducted; pyruvic acid is added; pH is adjusted; stirring is conducted for reaction; a sodium borohydride solution is added; stirring is conducted for reaction; cobalt chloride is added; the materials are placed; and a post-treatment is conducted to obtain modified chitosan; clove, radix astragali, rostellularia procumbens, galangal, rhizoma polygoni cuspidati and Chinese barberry root are mixed; the mixture is crushed; the crushed mixture is extracted with ethanol to obtain a composite traditional Chinese medicinal extract; nano-silica is added to an aceticacid aqueous solution; after dispersion, the chitosan and an emulsifier are added; the materials are stirred; pH is adjusted; blueberry leaf polyphenols, bamboo juice, paenibacillus polymyxa, malic acid, ascorbic acid, the composite Chinese medicinal extract, calcium chloride, glycine, gracilaria lemaneiformis oligosaccharides and compound essential oil are added; the materials are mixed evenly toobtain composite film coating liquid; mushrooms are pre-cooled; the pre-cooled mushrooms are soaked in the composite film coating liquid; and air-drying and storing are conducted.