Abstract: In order to realize high accuracy absolute radiometric calibration of large aperture integrating sphere source, the spectral radiance calibration method based on tungsten strip lamp was studied, then the spectral radiation uniformity calibration method through concentric scanning was discussed. An absolute radiometric calibration device was developed on this basis. The spectral radiance, luminance and color temperature of the integrated sphere source with the opening diameter of Ф300 mm were calibrated. The results of experiment prove that the uncertainty of spectral radiance absolute calibration is less than 4%.