The invention relates to a gravity unloading mechanism for solar array ground experiment, which comprises a thrust ball bearing, a bearing inner base, a bearing outer base, a cross beam, steel cables, pressure sensors and a display. The inner circle and the outer circle of the thrust ball bearing are respectively matched with the bearing inner base and the bearing outer base to form a moving component of an unloading mechanism; the bearing inner base is connected with the force bearing part of a solar array, and the bearing outer base is connected with the cross beam; the two ends of the cross beam are connected with the steel cables which are provided with the pressure sensors, and the two steel cables are hung on a mounting surface outside the system. The gravity of the solar array is transmitted to the external mounting surface through the bearing inner base, the thrust ball bearing, the cross beam and the steel cables, and is not born through a cavity driving motor any more, and simultaneously the free rotation can be guaranteed, therefore the mechanical environment that the driving motor provides torque for the solar array only and does not provide holding power for the solar array under zero gravity conditions can be simulated.