The invention relates to a nanometer-stage far infrared ceramic powder and a preparation method thereof, and is mainly composed of nanometer zinc oxide, nanometer titanium oxide, nanometer yttrium oxide, nanometer zirconium oxide, nanometer aluminium oxide, nanometer copper oxide, nanometer nickel oxide, nanometer silicon oxide, ultrafine tourmaline powder, ultrafine silicon carbide, and the like. The grain diameter of nanometer composite metal oxide is 20 nm to 60nm; the grain diameter of tourmaline and the silicon carbide is no more than 0.5um; and the preparation method adopts liquid phase settling method, the process flow contains: mixture making-solution-surface active agent adding-settling-filtering and washing-dehydration treatment-drying-fluid energy milling-high temperature composition-cribration-performance testing-standby, and the aim is to overcome defect that emission power of internal single-crystal infrared powder and composite infrared powder is lower at present.