The invention discloses a method for extracting 
glutathione. The method includes adding water, 
adenosine triphosphate, Y--
glutamic acid and 
cysteine synthase GSH I into L-
glutamic acid, L-
cysteine and 
glycine which are used as substrates, carrying out 
catalysis, adding 
glutathione synthase GSH II into the substrates, carrying out 
catalysis, carrying out two-step reaction to obtain 
mixed solution with 
glutathione, the Y--
glutamic acid and 
cysteine synthase and the glutathione synthase, separating the glutathione, the Y--glutamic acid and cysteine synthase and the glutathione synthase from one another to obtain low-concentration glutathione 
aqueous solution, the Y--glutamic acid and cysteine synthase and the glutathione synthase and allowing the Y--glutamic acid and cysteine synthase and the glutathione synthase to return systems to be reuse; carrying out low-pressure 
reverse osmosis concentration and high-pressure 
reverse osmosis concentration on the obtained low-concentration glutathione 
aqueous solution, then adding absolute ethyl 
alcohol into the glutathione 
aqueous solution, carrying out 
alcohol-
precipitation crystallization on the glutathione aqueous solution to ultimately obtain glutathione products and recycling and reusing ethyl 
alcohol solution. The method has the advantages that high-concentration glutathione solution can be obtained by the aid of the method, the usage of the absolute ethyl alcohol can be reduced during alcohol-
precipitation crystallization, 
energy consumption and the production cost can be decreased, the yield can be increased, the productivity can be improved, 
wastewater and 
waste gas can be prevented in production procedures, and accordingly the method is an environment-friendly, green and efficient production process.