Abstract: In order to realize absolute radiometric calibration of imaging spectrometer, based on stable source, a dedicated absolute radiometric calibration system was set up combined with monochromator, big caliber collimator and standard radiometer. Using substitute method, spectral irradiance of entrance pupil for measured imaging spectrometer was calibrated using standard radiometer during the calibration firstly, and then output signal of every pixel for measured imaging spectrometer was obtained. So spectral irradiance responsivity of every pixel could be calculated, the absolute radiometric calibration of imaging spectrometer in visible and infrared wavelength range was realized. The result of experiment proves that the uncertainty of absolute radiometric calibration is better than 5%.