To obtain an ideal interference pattern using an interferometer with a planar mirror structure, the moving mirror and the fixed mirror of the instrument are required to be conjugate to each other through the beam splitter in theory. However, a series of factors, such as changes in ambient temperature, vibration during transportation, shock environment during satellite launch, vibration interference from satellite platform may cause the tilt of fixed mirror relative to moving mirror, as a result, the performance of the interference spectrometer in orbit may degrade or even become unusable. Therefore, there is an urgent need for a calibration method to correct the collimation deviation of the instrument after its entry into orbit and to restore its performance.In this paper, a calibration system based on the attitude adjustment of the fixed mirror for interferometric spectrometers, which can be applied in space is designed and established. The system is primarily composed of interference signal acquisition unit, interference signal sampling unit, calibration controller, fixed mirror driving mechanism, moving mirror driving mechanism. This system is characterized by a large adjustment range, strong adaptability, and high reliability. Based on the peak-to-peak amplitude of the infrared interferogram, the attitude of the fixed mirror is adjusted to achieve optimal collimation and restore the performance of the instrument using ether command-control mode between the satellite and the ground or automatic-control mode.During the ground vacuum environment calibration tests of the interferometric spectrometer, both the remote-command-control mode calibration and the automatic-control mode calibration functions were tested. The peak-to-peak values of the interference signals and the instrument performance were evaluated after calibration using these two methods, The results indicate that the deviation in peak-to-peak values does not exceed 2%, and the NEDT is essentially consistent, which meets the design specifications of the instrument (Fig.9). The on-orbit calibration was performed for the HIRAS of FY-3F satellite, which utilizes this system. After calibration, the NEDT and the spectral responsivity of the instrument were significantly recovered. The average NEdT across the entire detection band decreased by 0.15 K, the spectral responsivity in the long-wave band improved by 3%, and the spectral responsivity in the two mid-wave bands improved by 7% and 15%, respectively. The instrument's performance meets the design specifications (Fig.10).The results from ground tests and on-orbit practical applications demonstrate that the calibration system can restore the instrument's misalignment within the designed adjustment range of 4500 μrad. The deviation in the peak-to-peak values of the infrared interference signals between the remote-command mode calibration and the automatic mode calibration does not exceed 2%. After calibration, the instrument's performance improved significantly. This system has achieved the first domestic correction of misalignment for on-orbit interferometric spectrometers and has been applied to multiple on-orbit interferometric spectrometers. Its development provides reliable support for ensuring that interferometric spectrometers can continue to operate with high performance under various adverse conditions.