The invention provides a method of microwave heating, solid-state reduction and gasification dephosphorization for manganese ore powder. The invention adopts a novel method of microwave heating, solid-state reduction and gasification dephosphorization against the characteristic of the manganese ore powder with high content of phosphorus. The method uses the manganese ore powder as a raw material, coal powder as reducing agent, and nitrogen as reduction and dephosphorization protecting gas to perform solid reduction and gasification dephosphorization in a reduction dephosphorization crucible, through raw material selecting, thinning, mixing, stirring and distributing, in an airtight microwave reduction dephosphorization furnace, in the nitrogen atmosphere, at a high temperature of 1390 DEG C, for 20 minutes to preserve heat and keep stand at constant temperature, so that the manganese ore powder can react with the coal powder and lime powder to prepare sponge ferromanganese powder; and manganese powder can be separated from phosphorus and hazardous substances via cooling, fine grinding and dry magnetic separation purifying. The yield of the sponge ferromanganese can reach 95 percent, the dephosphorization rate can reach 60 to 70 percent, and the phosphorus-containing rate is less than or equal to 0.15 percent. The manganese ore powder has the advantages of good reduction effect, high dephosphorization rate, short process flow and no environmental protection, and can be reused after phosphorus is collected.