The invention discloses a method for preparing Fagopyrum tataricum (L.) Gaertn. composite nano-state meal powder through a collaborative technique of microwave continuous drying and multistage ultra-fine crushing. The method comprises the following steps: preparing Fagopyrum tataricum (L.) Gaertn. powder, red date powder, red bean powder, Coix chinensis Tod. powder, amorphophallus konjac powder, rhizoma dioscoreae powder and oat powder respectively; evenly mixing the powder; carrying out microwave sterilization to obtain a finished product. According to the Fagopyrum tataricum (L.) Gaertn. breakfast powder disclosed by the invention, the Fagopyrum tataricum (L.) Gaertn., the Coix chinensis Tod., the red beans, the red date and the amorphophallus konjac powder are used as the raw materials, so that the nutrition is rich, the taste is good, and the breakfast powder also has effects of replenishing blood and beautifying, treating insomnia, nourishing heart and replenishing blood, strengthening the spleen and the stomach, eliminating edema, removing dampness and clearing away heat, and removing toxic substances and reducing fat; by carrying out techniques such as low-temperature baking, ultra-fine crushing and vacuum freezing and drying on the raw materials, the nutrition and the fragrance of the raw materials are preserved to a great extent, and a special baking fragrance is also given to the product at the same time; the prepared meal powder is so fine as to blend, and nutritive materials are more easily absorbed by a human body; and the meal powder preparation process disclosed by the invention is simple, is strong in maneuverability, low in energy consumption, easy for production, and has wide market prospects.