In order to master the satellite temperature change caused by thermal control system faults more easily and roundly, satellite thermal control system faults were sort into three basal classes： thermal resistance type, control strategy type,and passive heat load change. A dynamical model which can reflect the temperature change laws of satellite surface, radiator, indoor environment and key electrical equipment was also introduced. With this model the temperature changes caused by thermal faults can be conveniently simulated and this provides a mathematical model and simulation method for fault diagnosis and fault-tolerant control system design of satellite thermal control.