The invention relates to a preparation method of antidiabetic medicinal granules, pertaining to health care medicinal granules of the traditional Chinese medicine. The technological proposal is that the invention consists of the ingredients with the following weight proportions: 15-20 portions of astragalus root, 15-20 portions of ginseng, 20-25 portions of stigmata maydis, 20-25 portions of Gynostemma pentaphylla, 15-20 portions of rhizoma polygonati, 5-10 portions of rhizoma anemarrhenae, 20-25 portions of radices puerarire, 15-20 portions of broadleaf holly leaf, 15-20 portions of balsam pear, 10-15 portions of Salvia miltiorrhiza, 10-15 portions of scrophularia, 10-15 portions of rhiizoma dioscoreae from Hena of China, 15-20 portions of cortex lycii radicis, 10-15 portions of radices polygonati officinalis, and 10-15 portions of pollen. The antidiabetic medicinal granules has the advantages of precise and rational medicinal matching, abundant medicinal quantity, addressing both the symptoms and root causes, and has obvious functions and effects of heat clearing and toxicity removing, promoting the production of body fluid to quench thirsty, promoting blood circulation and removing blood stasis, supplementing Qi and nourishing Yin, lowering blood glucose, regulating blood fat and strengthening immunity.