The present invention discloses nutritious instant-brewing rice flour and a preparation method thereof. The nutritious instant-brewing rice flour comprises the following raw materials in parts by weight: 100 parts of rice, 10-20 parts of Chinese yam powder, 5-10 parts of black sesame seeds, 5-15 parts of spinach powder, 1-4 parts of sand worms, 0.5-1.5 parts of rhizoma curcumae longae powder, 2-5parts of shelled melon seeds, 0.1-1 part of sweet-scented osmanthus powder, 1-3 parts of bee pollens, 1-5 parts of spirulina platensis and 0.2-1 part of squid ink polysaccharide. The provided rice flour is rich in proteins, a variety of amino acids, vitamins, trace elements and other comprehensive nutrients, can supplement nutritional needs required by human body, and also has functions on enhancing immunity, preventing oxidation, strengthening stomach and nourishing stomach, moistening intestines and relaxing bowels, preventing and curing high blood sugar, high blood lipids and high blood pressure, beautifying features and nourishing skin, etc. The prepared rice flour has toughness, is smooth in mouthfeel, can ensure that nutrient composition is not damaged, and is prolonged in the shelflife and easy to realize industrial production.