Drug nanocrystal technology is an innovative formulation approach to increase the solubility of poorly water-soluble drug. Drug nanocrystals arouse more and more attention from pharmaceutical workers and researchers because of their features such as small particle size, high drug loadings, increased saturation solubility and accelerated dissolution velocity. Based on the literature at home and abroad, the characteristics of drug nanocrystals, solubilization mechanism, preparation technologies, stabilizer used in its preparation and market applications are reviewed.