Abstract: Aiming at the problem of inadequate experiment and training facilities in the nuclear power teaching, this paper analyses and comprehends the theory of LOCA surveillance system(LSS) system, including the core algorithm of loss of coolant accident(LOCA) machine.By using C# as the programming language,the simulation platform of LSS system is developed.The composition, function and construction method of the experimental platform are introduced.The experimental platform completes the simulation of LOCA algorithm and realizes the graphic and tabular display operation of the related data.The simulation results show that the platform is preferable to complete the function of LSS system.