Abstract: To ensure the stable operation of the balloon-borne coronagraph in the harsh near-space environment and to prevent damage to optomechanical components caused by extreme low temperatures, a temperature control system was designed. The system comprises 12 independently controlled thermal regulation units, each equipped with thermocouples as sensors and thin-fflm heaters as heating elements, combined with a PID control algorithm to achieve precise temperature management. By analyzing the structural characteristics of the coronagraph and the temperature and pressure conditions of its operating environment, a thermal exchange model for near-space conditions was established. Key factors inffuencing the coronagraph’s temperature and their relationship with instrument performance were investigated. Through multiple ground-based experiments simulating low-temperature and low-pressure conditions, the temperature control system demonstrated stable performance, ensuring that all operational parameters of the coronagraph met the expected standards. On October 4, 2022, the balloon-borne coronagraph system was successfully launched in Daqaidam, Qinghai Province. After 1.5 hours of ascent, it reached a stable altitude of approximately 30 km in the stratosphere, where it successfully conducted white-light corona observations and collected valuable data. Following the mission, the equipment was safely recovered, and operational data from the temperature control system were analyzed. The results conffrmed that the system design was robust, with stable operation achieving the desired temperature control outcomes and effectively protecting the coronagraph’s optomechanical components. This study provides signiffcant theoretical and practical insights, offering a valuable reference for the design of future temperature control systems for balloon-borne coronagraphs.