Abstract: The structural stress analysis in the rotor system of a high-temperature molten-salt pump was carried out based on ANSYS Workbench. At first,computational fluid dynamics software CFX was used to calculate the steady turbulent flows in the pump under multiple working condition,and the predicted results were validated with experimental data.By comprehensively considering the hydrodynamic,centrifugal and thermal loads in the high-temperature molten-salt pump,a flow-thermal-structure coupling dynamic model was established for the rotor system.Based on the model,the influence of material property and temperature on the structural performance of the pump was investigated,and the structural stress analysis in the rotor system components was conducted. The results show that under the same flow condition the maximum deformation of impeller blades in different materials shows a first increasing and then decreasing trend with increasing temperature. Moreover,the impeller deformation keeps constant basically and is less affected by flow rate.The stress level on the blade pressure side is higher than that on the blade suction side,and the stress value on the blade suction side in different materials exhibits a linearly decreasing trend at various temperatures. The position with the highest equivalent stress is mainly concentrated in the areas where the blades are in contact with the shroud and hub near the impeller outlet. Based on the comprehensive analysis on impeller deformation and strength,the impeller with stainless steel 316 L is the best solid mechanics performance compared with that in stainless steels 347 and 420. This study can provide some reference for the structural design of high-temperature molten-salt pumps.