Abstract: Hemihydrate calcium sulfate whiskers is a kind of modified reinforcement material with wide potential application and excellent performance. However，the quality and yield of hemihydrate calci⁃ um sulfate whiskers are limited to a wide range of applications. In order to promote the solution of the prob⁃ lem，based on a brief summary of the preparation methods of hemihydrate calcium sulfate whiskers，the re⁃ search progress of hydrothermal synthesis method，atmospheric salt solution method，organic reagent meth⁃ od and microwave heating method were emphatically introduced. And the advantages and disadvantages of different preparation methods were compared. The growth mechanism of hemihydrate calcium sulfate whis⁃ kers was elaborated，including the nucleation mechanism of hemihydrate calcium sulfate whiskers and reg⁃ ulatory mechanism of additive to hemihydrate calcium sulfate whisker. Meanwhile，the hydration process of hemihydrate calcium sulfate whiskers was introduced，which is of certain guiding significance for the prepa⁃ ration research，industrial production and application of hemihydrate calcium sulfate whiskers.

Key words: calcium sulfate hemihydrate whiskers, preparation process, growth mechanism, additive, hydration process