The invention relates to a stachyose infant nourishing cereal and its preparation method. The infant nourishing cereal comprises the following raw materials: long-grain rice, millet, whole milk powder, lactalbumin powder, stachyose, cane sugar, docosahexaenoic acid, arachidonic acid, vitamin and a trace element supplement accepted by bromatology. The especially added stachyose possesses obvious proliferation effects to probiotic groups like bifidobacterium and lactic acid bacillus in human gastrointestinal tract, and is capable of promoting the synthesis of vitamin B1, vitamin B2, vitamin B6,vitamin B12 and the like as well as promoting the absorption of elements like calcium and magnesium by the gastrointestinal tract, thereby the stachyose infant nourishing cereal has the advantages ofhigh nutrition value and high physiological value. The stachyose infant nourishing cereal can effectively preventing and alleviating the infant constipation and diarrhoea, inhibiting the intestinal tract diseases, comprehensive comprehensively enhancing the infant immunization capability and raising the disease resistance of infant body.