Abstract: In order to locate the fault in a test of a high-thrust LOX/LH2 engine, the dynamic characteristic simulation model library of liquid rocket engine is established, and the dynamic characteristic simulation model of the high-thrust LOX/LH2 engine is built. The accuracy of the simulation model is verified by comparing the model with the experimental parameters. According to the possible faults of the engine, the simulation calculation is carried out in turn, and the results are compared with the measured parameters. Through the comparison, it is found that the most likely failure mode is the blockage of the exhaust pipe of the oxygen turbine. The simulation results verified by experiments were in good agreement, which not only proves the accuracy of fault location, but also proves the feasibility of fault location of high-thrust oxyhydrogen engine by dynamic simulation, laying a foundation for further development of fault monitoring and location technology for high-thrust LOX/LH2 rocket engine in the future.