Abstract: New-generation agile satellites, which differ from traditional remote sensing satellites, require an active pointing and vibration isolation mechanism for the assembly of their camera and star sensor to achieve attitude maneuvering. This necessitates space for the assembly’s movement at the satellite cabin port, challenging the preparation and installation of thermal control multilayer insulation (TCML). This paper introduced a ‘layered collar’ installation and fixation method for TCML at the interface between the camera-star sensor assembly and the satellite cabin panel. Thermal testing of the entire satellite and on-orbit verification demonstrate that this method ensures the satellite’s temperature complies with design requirements, allows normal force decoupling of the assembly from the platform in orbit, and maintains good camera imaging quality. The study confirms the correctness and effectiveness of the proposed TCML preparation and installation method.