In connection with the new spatial heterodyne spectroscopy (SHS), integrated grating diffraction and space interference, a study on the spectral calibration technology is done. From interference mechanism of SHS, the spectral calibration difference between SHS and traditional dispersive spectrometer is analyzed, study on ILS, spectral resolution, bandwidth calibration principle and method of SHS is done, and spectral calibration method of tunable laser with integrating sphere is designed and calibration data processing algorithm according to hyper-spectral data features is explored. Finally, using the above method CO2 spatial heterodyne spectrometer is calibrated experimentally, and calibration accuracy is validated using magnesium lamp. The results show that spectral calibration method can meet the requirements of SHS spectral calibration, and are consistent with theoretical values of prototype.