The dynamic characteristics in the abnormal operation process of the gelled propellant space power system is dealt with in this paper. For the purpose of setting up the fault patterns of the space power system, the fault property equations and the normal mathematical models in the operation process were built. Then, four faults, including pipeline leak, filter jam, valve fault and nozzle ablation, were simulated by the visual C++ software. With an analysis of the results, some foundation for the intelligent fault diagnosis of the space power system in the future is provided.