Abstract: For more accurate and comprehensive analysis of the strength of rotating parts of a hydroelectric unit, first we numerically simulated the three-dimensional flow field in the hydraulic turbine using a CFD code. Then, with the calculation results used as initial conditions, simulations of fluid-structure interaction (FSI) were made to calculate the strength of each part under static loads and seismic loads separately. To calculate the dynamic coefficient of guide bearings, which have complicated structures with stiffness and damping factor varying significantly with the movement, a code of advanced rotating machinery dynamics (ARMD) was adopted. The results show that the method presented in this paper gives an accurate evaluation on the structural strength of a turbine and thus it is useful for the operation reliability analysis of those hydroelectric units that experienced earthquake disasters.