Abstract: Using KASKAD program package, the author make a research about the Tianwan nuclear power plant loading TVS-2M fuel assembly from the first cycle, also design the TVS-2M fuel assembly and on this basis, study fuel management, obtaining three fuel management cases, including year fuel cycle case and two long fuel cycle cases. In each program, the important parameters of the reactor core are analyzed and all the safety parameters meet the design requirements. In long fuel cycle program, TVS-2M is using from the first cycle and after the transition of only two cycles, the length of cycle reached the requirement of long period. The increased average annual capacity factor of the plant and the decreased times of overhaul during the core’s life which saving 30.8 percentage of the overhaul cost due to the long fuel cycle can largely improve the economic efficiency of the plant.