The invention relates to a method for preparing a nano powder material, and belongs to the field of inorganic synthesis and material chemistry. In the method, a crystalline hydrate of nitrate is taken as a raw material, anhydrous C2 to C4 alcohols are taken as a solvent, ethanolamine is taken as a precipitator; and the nano powder material, such as zirconium oxide, cerium oxide and the like, is prepared by a coprecipitation method. The method overcomes the defects of nonuniform precipitation, easy aggregation, need of special drying method and equipment, and the like in the conventional coprecipitation method in which water is taken as the solvent, and an inorganic base or an inorganic salt is taken as the precipitator; and the prepared nano powder material, such as zirconium oxide and cerium oxide has the advantages of small grain size (the grain size is 6 to 20nm), small particle size, narrow particle size distribution range (the particle size distribution range is 50 to 150nm), no hard aggregation, high sintering activity and the like. The prepared nano powder material is suitable for the fields of a solid oxide fuel cell, a chemical sensor, a special functional ceramic, a catalyst or a catalyst carrier and the like.