Nano-liposome method was used to prepare high-content polysaccharide liposomes from Bettila striata, and the interaction mechanism between them and tyrosinase were studied. The results showed that the average particle size of the prepared polysaccharide liposomes was 5.72 μm and the particle size distribution was uniform; when the concentration was 12.8 mg/mL, the inhibition rate of these polysaccharide liposomes on tyrosinase activity was 51%, and the half inhibitory concentration was 11.56 mg/mL. Spectral analysis showed that the polysaccharide liposomes from B. striata could interact with tyrosinase, with the binding constant of 6.58×10⁵ L/mol; the fluorescence quenching mechanism was mainly static quenching, whose effect enhanced with the increase of polysaccharide concentration, and the number of binding sites was 1.071 1.