The invention provides a medicated food composition used for adjusting and assisting of blood glucose lowering. The raw materials comprise a blood glucose lowering composition, a conditioning composition and a detoxifying composition, specifically, 40-60 % of the blood glucose lowering composition, 30-50 % of the conditioning composition, and 1-20 % of the detoxifying composition, wherein the blood glucose lowering composition comprises fructus momordicae charantiae, folium mori, radix puerariae and L-arabinose, and the ratio of fructus momordicae charantiae to folium mori and radix puerariaeto L-arabinose is 2 to 2.2 to 1.1; the conditioning composition comprises fructus mori, radix astragali, radix ginseng, poria cocos and rhizoma polygonati, and the ratio of fructus mori to radix astragali, poria cocos and rhizoma polygonati to radix ginseng is 1 to 5 to 1.6; the detoxifying composition comprises corn stigma. The invention further provides a preparation method of the medicated foodcomposition. According to the medicated food composition, the ingredients are reasonably compounded, blood glucose is reduced in a synergistic manner, the efficacy of reducing blood glucose is improved, meanwhile, the effects of tonifying the liver and the kidney, replenishing blood, and tonifying Qi are achieved, the body is regulated from many aspects, the immunity is improved, and the cure rate for diabetes is improved to 98%.