Abstract: In the space environment simulation test,we use heat sink below-173 ℃ to simulate the space environment.The simulation error can be controlled at about 1%compared with the real space environment.With the development of deep space exploration,especially with the proposal of Mars exploration mission,the temperature of Mars surface is-123~27℃.The traditional single-phase liquid nitrogen cycle can not meet the needs of Mars exploration simulation test,so the technology of temperature-adjusted heat sink is indispensable.In this paper,we use nitrogen to regulate the temperature of heat sink,and calculate the key parameters of the system.