Spacecraft solar wings, antennas, and other space deployment mechanisms need to be unloaded by gravity during the ground launch test. At present, the most widely used is the guide rail type Micro-gravity unfolding frame, and the rail needs to be adjusted horizontally before the test is carried out. Aiming at the shortcomings of the current rail debugging relying on labor, difficult high-altitude operation, and low debugging efficiency, a guide rail automatic attitude adjustment device is proposed, which can quickly realize the efficient adjustment and attitude maintenance of the rail level. After test verification, the system can increase the local level of the guide rail from the traditional 0.02 mm/m to 0.01 mm/m, the overall level from the original 0.1 mm/m to 0.02 mm/m, and shorten the commissioning time from the original 4 h to 1 h. The power-off holding ability is strong, which greatly improves the efficiency of the ground test. The research results have been applied to other spatial deployment institutions that conduct tests based on rails.