A thermal control system of electric cabinet in a high-resolution space camera was designed to resolve its heat dissipation. The basic flow sheet of thermal design for the electric cabinet was introduced,and several kinds of approaches in thermal conductions and thermal radiation were used to dissipate the heat for the electronic components, Printed Circuit Boards (PCBs) and their chassises.Then, the finite element mode of thermal analysis was corrected according to the thermal test in the vacuum condition.Based on the results of thermal test and thermal analysis, the thermal design was modified by adding a heat pipe additionally. Finally,according to the space environment and structure characteristics, the thermal analysis for the thermal control system was performed by the corrected mode and the case temperatures of the electronic components were calculated. The results show that the case temperatures of electronic components are from 40.2 ℃ to 62.7 ℃ after adding the heat pipe, which means the thermal design scheme is feasible and reasonable for the electric cabinets of space cameras.