To study the preparation method of stable powder of zirconia, which was good dispersion and narrow size distribution. In the experiment, stable zirconia nano powder were prepared by hydrothermal hydrolysis process. The effect of hydrothermal time, pH, temperature and organic additive glycerol on the particle size, crystalline and stability of the zirconia powder were investigated experimentally. The preparation samples of nano zirconia powder under different hydrothermal conditions were characterized by using XRD and SEM analysis technology. The crystallinity rises with the increase of the hydrothermal temperature. With the increase of the hydrothermal temperature from 150 ℃ to 250 ℃, the particle diameter increases first, and then decreases because nucleation rate increases rapidly; The pH values of the reaction solution influence the crystallinity of sample. Selecting a suitable pH value can reduce reunion between powder particles and improve the dispersion of powder. The average partical size of the samples increases with reaction progresse. Zirconia powder doped with 3% Y and Glycerol prepared at 200 ℃, pH=10, t=12 h and then calcining them at 1000 ℃ for 12 h, has good dispersion, narrow particle size distribution, and a single cubic phase. The samples of nano stable zirconia powde of controllable particle size were prepared by setting the hydrothermal hydrolysis conditions, and Yttrium doped effectively improve the stability of zirconia. The addition of glycerol could improve evidently the stability and dispersion of zirconia powder, calcination stabilized zirconia nano powder could effectively reduce partical size distribution and improve the crystalline.