The invention discloses quinoa cereal meal replacement powder and a preparation method thereof. The quinoa cereal meal replacement powder is prepared from the following raw materials in parts by weight: 30-40 parts of quinoa, 7-9 parts of polished round-grained rice, 7-8 parts of coix seeds, 6-8 parts of broom corn millets, 6-8 parts of buckwheat, 3-4 parts of red adzuki beans, 3-4 parts of blackbeans, 1-3 parts of mung beans, 2-3 parts of Chinese wolfberry fruits, 2-4 parts of lucid ganoderma, 2-3 parts of Chinese yam, 2-3 parts of haws, 2-4 parts of water chestnuts, 1-2 parts of spinach, 1-2 parts of beet, 4-5 parts of kiwi fruits, 4-5 parts of pineapples, 2-3 parts of calcium gluconate, 2-3 parts of ammonium ferric citrate, 3-5 parts of maltodextrin powder and 3-5 parts of skim milk powder. The quinoa cereal meal replacement powder prepared by mixing the quinoa which serves as a main raw material with multiple cereals, fruits, vegetables and dairy products has a unique taste and rich nutrition for balanced nutrition supplement, can be used for effectively reinforcing the body function performance and regulating the immunity, improving the body stress and preventing diseases andobesity, is suitable for people of all ages for natural health maintenance, and is especially suitable for people losing weight.