Method for preparing ultrafine barium titanate material

The invention discloses a method for preparing an ultrafine barium titanate material. A high-temperature solid-state method is adopted. The method comprises the following steps of: (A), grinding a barium carbonate powder raw material into barium carbonate powder with fine particles by a mechanical method, wherein the average particle size of the barium carbonate powder obtained through grinding can be reduced to 0.05 to 0.2mu m, the particle size distribution is that D90 is less than or equal to 0.6mu m, and the specific surface area is more than 8m /g; and (B), mixing the barium carbonate powder with the fine particles obtained in step A and titanium oxide powder which has a 100 percent rutile crystalline phase, and calcining to obtain barium titanate powder. The barium titanate powder prepared by the method is high in purity, small in particle size, and high in specific surface area and crystallinity; and the barium titanate powder is suitable for ceramic capacitors of which the layer number is more than 200, the thicknesses of dielectric films of the ceramic capacitors are less than 4mu m, particle sizes of calcined crystal grains are less than 0.5mu m, and the ceramic capacitors meet X5R characteristics.