To meet the requirements of power grids, the pumped storage unit (PT) has to operate at transient conditions. As the unstable fluid is one root cause of unit instability in pumped storage plant, accurate solutions to PT internal fluid should be highlighted. This review of numerical solving methods for the internal fluid of PT consists of three parts. First and foremost, common turbulent models are described and both the advantages and disadvantages of each turbulent model are clarified. The second part is auxiliary models for achieving better authenticity in numerical study, wherein transition models, multiphase models, and cavitation models are systematically interpreted. New solving methods for better flow field analysis are stated lastly, such as dynamic mesh technique, genetic algorithm and some new experimental equipment, and so on. This article provides a comprehensive reference to the study of PT internal fluid. In order to illustrate the fluid characteristics more accurately, it is of great significance to conduct in-depth research to explore suitable turbulence models. Consequently, exploring universal solving methods with better performance is extremely necessary for current requirements of hydraulic machinery under transient processes.