Abstract: In the thermal control design of a stacked extravehicular load, in order to meet the simultaneous requirements of heat dissipation of the whole machine as well as high-precision and high-stability thermol control of some module components, a thermal control design scheme based on thermo electric cooling (TEC) was proposed. It was to create a relatively low temperature environment on the side wall of the upper module, i.e. primary thermol control, while use a thin-film electric heater to control the temperature of internal components of the upper module with high stability, i.e. secondary thermol control. By establishing and effectively controlling the only heat transfer path between the upper module and the cold plate, efficient heat dissipation of the upper module and the high temperature stability for the internal constraint points are realized. The thermol control scheme was verified by simulation analysis and thermal balance test. The results show that, when the incoming flow temperature of the cold plate fluctuates between ±5 ℃/90 min, the primary and the secondary thermal control achieve temperature fluctuations less than ±0.3 ℃/90 min and ±0.1 ℃/90 min at constraint point, respectively. The temperatures of all constraint points satisfy the requirement of design index.