Abstract: Based on Super-Critical Water Reactor（SCWR） conceptual configuration design,with the shell made by 508-III low alloy forging and the outlet nozzle and steam cavity made by Inconel 690 forging,this paper focuses on the application of Computational Fluid Dynamics（CFD） in the numerical simulation of SCWR outlet nozzle and steam cavity structural design.The temperature distribution of outlet nozzle and steam cavity on the Super-Critical condition has been obtained in this study.The simulation results indicate that the maximum temperature reaches 547K at welding line between 508-III shell and Inconel 690 nozzle,thereby it is feasible for conceptual configuration design and materials of SCWR outlet nozzle and steam cavity,and it will assist in validating the direction of configuration optimization and material selection for the design activities.