The invention relates to the technical field of a medicine formula, and discloses a blood sugar lowering medicine. The blood sugar lowering medicine comprises radix aconiti lateralis preparata, cassiatwig, Asarum Herb, dried ginger, coptis, phellodendron amurense, dark plum, Poria cocos, polygala root, Ophiopogon japonicus, Chinese magnoliavine, calamus, Morinda officinalis, cornus officinalis, oriental waterplantain rhizome, mint, Polygonatum and American ginseng. The invention also discloses a method for preparing the blood sugar lowering medicine. The preparation method of the blood sugarlowering medicine is simple, the preparation cost is low, and the prepared medicine is a pure natural Chinese medicine preparation, and is suitable for a wide range of people. The blood sugar loweringmedicine has the effect of treating diabetes, but also improves the body's microcirculation and improves the system immunity, and is suitable for people's efficient and fast-paced lifestyle and healthy consumption idea; the preparation method of the invention is quite different from traditional treatment methods, is better than traditional treatment methods, and the medicine has fewer side effects.