Abstract: In order to optimize the thermal model of Mars rovers and to verify the system functions in the Martian extreme environments, it is necessary to test the Mars rover in a comprehensive simulated environment on the ground. On the Mars surface, the ambient temperature sees a great variation with the alteration of day and night. It is a difficult task to simulate the surface temperature of Mars on the ground. This paper propose a method by using the GN₂ temperature adjustment system to realize the thermal environment simulation and the temperature control of the Mars’ surface. The diurnal gas temperature simulation of Mars from -105 ℃ to 5 ℃ at a pressure of 150 Pa and 1400 Pa is realized in the transient way, with the maximal temperature difference not more than 10 ℃, and the repeatability error is comparatively low.