Abstract: Modeling and simulation of controlled-object temperature changes are necessary for developing satellite thermal control system. In order to calculate the dynamical properties of satellite thermal control system more easily, the whole satellite was divided into five lumped thermal control nodes, which included satellite's outer surface, heat radiator, indoor environment, key electrical equipment and phase change device. The heat transfer relationship between different nodes and temperature change properties of each part was carefully considered during the node dividing process. Mathematical models for temperature changes of each thermal control node were built and presented. With these dynamical models above, the key temperature changes of satellite, causing by either indoor heat source disturbs or outer side space heat flux varieties, could be calculated more simply and conveniently than using the common unsteady temperature field calculating method. This satisfies the stringent demand of thermal control system's control strategy optimization and its simulation. It's especially useful in developing active thermal control systems.