The invention relates to an optic-thermal coupling environment ground simulation device for different orbit altitudes of space. The device comprises a solar simulator, a background radiation simulator, a vacuum chamber and a movable heat sink; the solar simulator comprises a multipath xenon lamp projection optical system and is arranged at the top of the vacuum chamber, multiple window mirrors arearranged at the top of the vacuum chamber, and all paths of system light beams irradiate the interior of the vacuum chamber after penetrating through the window mirrors; the movable hot sink is movably arranged in the vacuum chamber, multiple window mirrors can be shielded, refrigerating and cooling can be conducted by introducing liquid nitrogen, and quick switching between sunlight and shadow is achieved; the background radiation simulator is arranged inside the vacuum chamber and located below a spacecraft model; the background radiation simulator comprises multiple arc radiation blocks, apower source and a liquid nitrogen source, firstly, all the radiation blocks form annular areas with different radii, and all the annular areas with different radii are concentrically distributed toform the whole radiation face of the background radiation simulator. By means of the device, simulation of an optic-thermal coupling environment under different orbit altitudes and different radiationstates can be achieved.