The invention relates to a medicinal liquor capable of reducing blood sugar and preventing and treating diabetic complications, which is prepared by a buckwheat wine and the Chinese medicinal herbs including frosted folium mori, folium ginkgo, cordyceps militaris, radix puerariae, fructus crataegi, flos carthami, dried sanguisuga and semen litchi etc. Compared with the prior art, the formula provided by the invention is scientific, the prescription is reasonable, and the medicinal liquor is capable of stably reducing the blood sugar, urine sugar and glycosylated hemoglobin, improving glucose tolerance indexes, simultaneously reducing blood fat, blood viscosity and blood pressure, improving the blood circulation, and alleviating insufficient blood supply to heart, brain and nerves; and meanwhile, the medicinal liquor is capable of effectively improving the symptoms, such as palpitation, cephalalgia, cardiopalmus, cutaneous pruritus, hypopsia, numbness of limb, cold hands and feet, insomnia and vexation and fatigue, and the product is free from toxic and side effects, so that the medicinal liquor is suitable for long-term drinking.