The invention belongs to the technical field of fully-fermented green tea liquor brewing, and particularly relates to a method for preparing green tea liquor. The green tea liquor is obtained through fermentation of green tea extract and tea leaves, is mild beverage liquor with the alcohol content of 4-18%, and is obtained by conducting fermentation twice under certain pressure (0.8 mpa) during brewing. The green tea liquor has the advantages that various nutrients which can not be completely dissolved in water during tea making and drinking at ordinary times can be completely dissolved out through fermentation and reaction with alcohol, so that the comprehensive utilization rate of tea is increased greatly, and the nutritive value of the green tea liquor is increased. The key to success of fermentation of the green tea liquor is yeast selection. Years of practice proves that the green tea liquor fermented with the dedicated tea liquor yeast prepared by the inventor tastes mellow, rich and sweet and has a lasting aftertaste. The technical problem that bitter taste and sour taste can be generated when green tea liquor is brewed with other yeast is solved.