Astilbil nanosuspension (AT-NS) was prepared by an antisolvent precipitation method. The formula and process of AT-NS were optimized by the single factor experiment. AT-NS was prepared under the optimal conditions, and its morphology and crystallinity were characterized. In vitro release of AT-NS was also determined. The particle size of AT-NS stabilized by PVP K30 was (149±3) nm, and the polydispersity index (PDI) and stability index (SI) were 0.137±0.014 and 0.940±0.012, respectively. The results of SEM showed that AT-NS was spherical. Both XRD and DSC showed that AT was amorphous in nanosuspension. In the in vitro release test, AT-NS showed a significantly increased dissolution. This simple low-cost approach could prepare AT-NS successfully. AT-NS could significantly improve the dissolution of AT and provide the reference to break the limitation on the clinical application of AT.