In order to guarantee the normal work and mapping accuracy of mapping cameras, a thermal control system for the mapping cameras was designed and tested by the thermal balance tests.Firstly,the thermal environment of a mapping camera was analyzed,and the external thermal flux of the pupilin the mapping camera was calculated.Then, the thermal design of the mapping camera was carried out.A passive thermal control system was used to control the temperature of the camera to reduce the sensitivity of mapping camera to the external thermal environment.An active thermal control system was taken to carry out the temperature compensation to reduce the axial and radial temperatures of the mapping camera.Finally,three extreme test conditions were designed and thermal balance tests were undertaken according to various job models and different thermal environments.The test results show that when the thermal design system is working,the temperature fluctuations of the mapping camera are at (18±2) ℃,the axial and radial temperature differences are less than 4 ℃ and 0.5 ℃, respectively,and the temperature of the mapping base is (18±3) ℃.It is shown that all the temperature indicators in the mapping camera are able to meet the system requirements.