The invention discloses a traditional Chinese medicine for lowering blood sugar, which is characterized by consisting of the following components in weight: 10-25g of panax quinquefolium, 10-25g of radix astragali, 10-25g of rehmannia roots, 10-25g of Chinese yam, 10-20g of radix salviae miltiorrhizae, 10-20g of radix puerariae, 10-20g of Chinese wolfberry fruits, 12-20g of semen cuscutae, 12-20g of cortex lycii radicis, 10-20g of radix polygonati officinalis, 8-15g of asparagus cochinchinensis, 10-15g of raspberry, 10-15g of Chinese trichosanthes roots, 8-15g of rhizoma anemarrhenae, 10-15g of cornus officinalis, 8-12g of scutellaria baicalensis, 8-12g of radix glehniae and 8-12g of alpinia oxyphylla. The traditional Chinese medicine for lowering blood sugar is reasonable in prescription, simple to prepare and convenient to take; and as proven by years of clinical application, the traditional Chinese medicine is remarkable in curative efficacy, mild in medicine property and free of toxic and side effects, and has an effective rate of 93% and an efficiency playing rate of 87%.