Tape-casting method and template grain growth (TGG) method are widely used in studying (Na0.5 Bi0.5) TiO3 based ceramics, and it is a very important procedure to prepare Bi4Ti3O12 powder with anisotropy. Bi4Ti3O12 powder with anisotropy was prepared by NaCl-KCl molten salt method. The influence of nonstoichiometry Bi2O3 on the phase structure and microstructure of Bi4Ti3O12 powder was investigated, and the technical parameters were optimized. The growth mechanism of Bi4Ti3O12 in molten salt was discussed. The result showed that the average size and uniformity degree of Bi4Ti3O12 powder increased with the increasing of excessive nonstoichiometry Bi2O3 content, and the average size reached the best value of 8-10μm at the 7.5% of excessive Bi2O3.