Abstract: Temperature adjusting system is an important system of space environment simulator to carry out the T/V & T/B tests for spacecraft. It can adjust thermal shroud temperature continuously between -100℃ and +100℃, and stabilize the temperature at any point within the range. Compared with such temperature adjusting equipments as cooler with liquid nitrogen tank or thermal shroud at liquid nitrogen temperature with infrared heating cage, the temperature adjusting system with jetting liquid nitrogen can reduce energy consumption and decrease expenditure. It is difficult to use the system in large environmental simulator for its thermal lag and unevenness between different heat sink branches. The jetting liquid nitrogen system fits the facts and requirements of KM6 in design . The results of temperature adjusting system with jetting liquid nitrogen of a large space environment simulator indicate that it has achieved comparative level in the same field in the world.