Mechanism of production of rotor-stator interaction with the cascades match composed of runner blades and wicket gates is analyzed aiming at the problem that there is vibration during operation of pump turbine in pumped storage power station. Influence of different cascades matches on hydraulic excitation force is studied based on dynamic response of runner to hydraulic excitation mode. Finite element analysis on dynamic characteristics of hydraulic turbine components including runner, wicket gate, head cover and bottom ring are carried out by using fluid structure interaction method and corresponding model. The resonance possibility of structure excited by fluid is stated for cascades match 7/20. In order to avoid resonance of hydraulic turbine components and the consequent fatigue crack and fracture accident, selection principles of optimal cascades matches, methods of reducing pressure fluctuation in vaneless space and concrete measures for increasing natural frequencies and reducing factor of stress concentration of structures are proposed.