Abstract: In response to the challenges of complex external heat flow and the stringent temperature control requirements for the optical system and primary support structure of a large aperture space remote sensing camera in a low-inclination circular orbit, a comprehensive thermal control strategy has been developed. The strategy for the primary support structure integrated an indirect radiation technique with a high-precision discrete temperature control algorithm, achieving stable temperature control with a full-cycle variation within ±0.3 ℃ for the optical-mechanical structure. To manage internal heat sources, efficient heat dissipation was realized through rational allocation of heat dissipation surfaces, differentiated strategies, optimized component layout, and effective establishment of heat dissipation pathways. A heat dissipation surface coupling temperature equalization technique was particularly effective for the cold and hot ends of the refrigerator. Thermal balance tests and on-orbit flight data confirm the efficacy of the camera’s thermal control system design. The research offers a valuable reference for the thermal control design of similar remote sensing instruments.