The invention belongs to the technical field of wine brewing, and provides a method for brewing fen-flavor daqu liquor by adopting buckwheat, for solving the problem that the existing wine brewed by buckwheat is of soy sauce flavor type but not of fen-flavor type, while the fen-flavor white spirit is brewed by adopting sorghum but not buckwheat, so that the content of nutritional ingredients in the white spirit is low, and a health-caring effect can not be achieved. The method comprises the following steps: finely selecting and processing raw materials, moistening grains and steaming the grains, adding water into the grains, pouring out of a steamer, placing the grains into a pond for fermentation, discharging the fermentation product out of the pond, adding auxiliary materials into the fermentation product, carrying out distillation, intercepting the foreshot and removing the tailings to obtain original pulp liquor, discharging the original pulp liquor out of the steamer, and carrying out secondary fermentation on fermented grains. The brewing method is simple, and does not use complicated equipment, so that the method is suitable for promotion; the fen-flavor daqu liquor is clear and transparent in color, has the compound fragrance including the main fragrance of ethyl acetate and rich fragrance of buckwheat, is soft-sweet and tasty, has long after-flavor in the mouth, has the efficacies of invigorating spleen and supplementing qi, whetting the appetite and loosing intestines, relieving food retention to resolve stagnation, removing humidity and descending qi, lowering blood fat and cholesterol of the human body, softening blood vessels, protecting eyesight, preventing cerebrovascular hemorrhage, promoting metabolism of the body, enhancing the detoxifying capacity, and resisting embolism; the fen-flavor daqu liquor further has the effects of resisting bacteria, diminishing inflammation, relieving cough, preventing asthma and eliminating phlegm.