The invention discloses a medicated diet composition capable of conditioning and treating food deficiency, loose stool, pant and weakness, and a preparation method of the medicated diet composition. The medicated diet composition comprises the following raw materials in parts by weight: 3-15 parts of bighead atractylodes rhizomes, 3-15 parts of poria cocos, 5-20 parts of radix codonopsis, 3-15 parts of semen cuscutae, 1-8 parts of Chinese magnoliavine fruits, 1-8 parts of cinnamon, 1-8 parts of platycodon roots, 1-8 parts of amomum xanthioides kernels, 15-35 parts of lotus seeds, 10-25 parts of Chinese yams, 1-8 parts of dried orange peel, 5-20 parts of white hyacinth beans, 3-15 parts of radix glycyrrhizae preparata and 1 pig kidney. The preparation method comprises the following steps ofplacing the raw materials in water, and performing soaking for 20-40 minutes so as to obtain a mixture A; thoroughly cleaning the pig kidney, and removing fascia; and placing the treated pig kidney into the mixture A, performing boiling over with a strong fire, and performing cooking with a mild fire for 0.8-2 hours until the pig kidney is thoroughly cooked so as to obtain the medicated diet composition. The medicated diet composition disclosed by the invention has the efficacy of reinforcing the spleen, benefitting the lung and generating kidney essence, and has the effect of treating and conditioning diseases of food deficiency, loose stool, pant, coughs, sleepy and weary bodies, weakness and the like, caused by deficiency of the spleen and the stomach. Food materials and medicinal materials selected for the medicated diet composition are common and are low in price, and the medicated diet composition is simple to make, notable in treatment effects, free from toxic and side effectsand worth of popularization and eating.