The invention relates to high-dietary fiber five-cereal puffing powder and a preparation method, and belongs to the field of food processing. The five-cereal puffing powder comprises the following raw materials: coarse rice powder, wheat meal, oatmeal, millet meal, glutinous corn meal, soybean meal, wheat bran meal, calcium lactate, ferrous gluconate, zinc gluconate, vitamin B1, vitamin B2 and vitamin B6. A method for processing the five-cereal puffing powder comprises the following steps of: screening coarse cereals, grinding, milling, sieving with an 80-mesh sieve, mixing uniformly in a ratio, adjusting the moisture of materials, balancing the moisture, extruding and puffing by using double screws, drying, crushing, and sieving with a 100-mesh sieve, enhancing mineral elements and the vitamins. The high-dietary fiber five-cereal puffing powder has the characteristics that the puffing powder is prepared from natural grain coarse cereals, emulsifying agents and sweeteners are not added, the mineral elements and the vitamins are enhanced, the content of dietary fibers reaches the specified standard of national high-dietary fiber foods, and the puffing powder can be eaten only by being infused by boiling water, so that the high-dietary fiber five-cereal puffing powder is an ideal nutritional and convenient food which is suitable to be eaten by middle and old-aged people.