The invention provides a medicine for treating diabetes. The medicine comprises the following active ingredients through being metered by weight: 10 to 25g of codonopsis pilosula, 5 to 15g of radices trichosanthis, 10 to 20g of yam, 5 to 25g of safflower carthamus, 15 to 30g of cordyceps sinensis, 10 to 18g of cistanche, 6 to 10g of dendrobe, 15 to 25g of radix ophiopogonis, 5 to 18g of schisandra chinensis, 15 to 25g of liquorice, 15 to 20g of rhizoma atractylodis alba, 10 to 15g of rehmannia root and 5 to 20g of coptis chinensis. The medicine is not used for directly reducing the sugar content, the blood microcirculation is promoted through recovering and improving the human body organ functions via various kinds of traditional Chinese herbal medicine, the human body immunity is improved, the generation and the secretion of insulin in the human bodies are increased, and the natural sugar reduction goal is reached. Each kind of adopted medicine does not have toxic or side effect on the human bodies and contains various nutrition ingredients. Through the clinic observation on hundreds of early stage people with slight symptoms, the curing goal can be reached through the single use of the medicine, the matched use of the medicine with insulin and other hypoglycemic medicine can be adopted, and the universal dosage can be reduced.