In order to keep the temperature of CCDs on an attitude varied space camera within a limited range, a thermal control system of the CCD Focal Plane Assembly (CFPA) is designed. Base on the theory of differential thermal expansion between the two materials having different CTE values,a thermal switch as a crucial part in the thermal control system is designed. According to the calculation of the orbit, the obstructive relation of all parts and the characteristics of attitude varying, the scheme of two radiators controlled by a thermal switch is presented, and the thermal design of the CFPA is specified. The performance of the thermal design is simulated by the TMG software. The results indicate that the temperature fluctuation of the CCD is 12.34 ℃ under passive-thermal-control, whereas it is only 1.73 ℃ under both passive-thermal-control and active-thermal-control. Experiments show the thermal control system can meet the need of the mission and the thermal design is efficient and reasonable.