Preparation method of mushroom extracting solution rich in ergothioneine and nicotinamide

The invention discloses a preparation method of a mushroom extracting solution rich in ergothioneine and nicotinamide. The preparation method comprises the following steps of: adding chitosanase displayed on the cell surface, vitamin C and distilled water into a certain amount of mushroom freeze-dried powder, controlling the extraction temperature to be 40-60 DEG C, and controlling the pH value to be 5.5-6.5; and after extraction is finished, removing mushroom residues through filtration or centrifugation, further carrying out microfiltration and ultrafiltration on collected filtrate to remove the chitosanase displayed on the surface, and carrying out sterility detection on the filtrate. The extracting solution obtained by non-high-temperature treatment of mushrooms is rich in antioxidant and anti-inflammatory active matters such as ergothioneine and nicotinamide, and can be used as a cosmetic raw material to achieve the skin care effects such as oxidation resistance, inflammation resistance and allergy resis