Firstly, precipitate with anhydrous ethanol to make the final concentration of the solution reach 80%, that is, add 4 times of anhydrous ethanol to dissolve the lipid in ethanol, and remove other precipitates with TCA (trichloroacetic acid method), with the amount of TCA being 3% of the mass. TCA mainly destroys protein structure, and the content of protein can be detected by Coomassie brilliant blue method. Finally, small molecular substances such as ribose can be removed through dialysis bags.