The embodiment of the invention relates to a
modal test structure temperature compensator in a vacuum environment. The
modal test structure temperature compensator comprises a thermal vacuum test boxbody, an upper compensation plate and a lower compensation plate, the upper compensation plate and the lower compensation plate jointly form the
temperature compensator, a test piece is fixed on the inner rear wall of the thermal vacuum test box body, and the upper compensation plate and the lower compensation plate are respectively positioned on the upper side and the lower side of the test piece, are made of the same material, have the same
thermal load as the test piece, and cover most circumferential positions of the test piece to effectively reduce the
radiation heat of the test piece tothe surrounding space; and an annular base is used for fixedly connecting the upper compensation plate and the lower compensation plate to the inner rear wall of the thermal vacuum test box body, threaded holes are used in cooperation with screws, and the annular base is fixed to the rear wall of the interior of the thermal vacuum test box body through the screws, so the upper compensation plate and the lower compensation plate are stably connected through the connecting mode, thereby vibration caused by external force is avoided, and the test piece is prevented from being affected.