Abstract: The working condition of pumped storage power station is complicated, and its frequent working-mode conversion leads to severe pressure fluctuations in the pipeline and badly-deteriorated flow performances. Vibrations are a significant factor in the safe operation of units, especially more serious at the stages of start-up, shutdown, and load rejection. For the Guangzhou pumped storage power station plant A, we have calculated the variations in pipe pressure using a one-dimensional numerical method, and compared the calculations of pressure at spiral case outlet and rotation speed, etc. with its test data of transient processes in typical conditions. A three-dimensional numerical model was developed and applied to simulations of axial hydraulic thrust at different guide vane openings, focusing on analysis of the start-up and shutdown stages of power generating operation.