Abstract: Nanocrystal drugs have many advantages, such as no carrier materials, easy industrialization, diversified dosage forms, and can significantly improve the solubility and bioavailability of insoluble drugs, so many drugs have been on the market. The traditional nanocrystal preparation technology has the problems of low preparation efficiency and process limitation of the smallest achievable particle size. With the progress of pharmaceutical preparation technology, the preparation technology of nanocrystal drugs is constantly improving, and new preparation technologies are constantly emerging. The emergence of new technologies has greatly shortened the process time and makes it possible to prepare nanocrystal drugs with smaller particle diameters. In this paper, the preparation technologies of nanocrystal drugs, especially the new preparation technologies such as high gravity controlled precipitation, microfluidic reaction technology and various combination technologies, are reviewed from three aspects:"Top-down" technology, "Bottom-up" technology and combination technology. This article also prospects the development of new preparation technologies, hoping to provide reference for the related research of nano-preparations.