The invention relates to a method for preparing non-meat source red-braised beef powder by using defatted soybean meal and yeast extract, the method can effectively solve the production of the non-meat source red-braised beef powder and meet the needs in the lives; the technical proposal for realization is as follows: the non-meat source pure natural raw materials of the defatted soybean meal, the yeast extract and corn starch and the like are concentrated, degraded, rearranged and carried out the thermal decomposition reaction in a twin-screw extrusion-expansion machine, a micro-porous expanded solid is obtained, the micro-porous expanded solid is matched with other seasoning liquid and compound amino acid components in a soaking way, the micro-porous expanded solid is sent to a belt dryer by using the continuous way for carrying out the drying, then non-meat source meat flavor powder is prepared, and the non-meat source meat flavor powder is further combined with other components toprepare the seasonings with various flavors, that is, the non-meat source red-braised beef powder. The non-meat source red-braised beef powder is a substitute of beef-source meat flavor powder, the yield is high, the cost is low, the protein content is high, the aroma and the flavor are thick and vivid, the wide and harmonious beef flavor from the stewing to the barbecuing can be formed, thereby having good economic and social benefits.