The invention relates to a nutritional porridge mixture and a preparation method thereof, belonging to the technical field of production and processing of nutritional foods. The food mixture consists of coarse cereals, vegetables, fruits, dried fruits, nuts, seeds, beans, funguses, alga and special foods. According to various characters and different qualities of the foods, the foods are treated by a method and a process of washing, soaking, washing, airing, steaming, boil-drying, air drying and sun drying, then the dried food products are mixed together, milled in a flour mill and sent to a molding machine to be prepared into oatmeal, and finally the products are subjected to vacuum packaging under the illumination of an ultraviolet sterilizing lamp. The nutritional porridge disclosed by the invention is free of any food additives, anti-corrosive agents, sugar, salt and the like, so the original taste and flavor as well as the natural nutritional ingredients and effects of the foods are retained.