Abstract: To meet the requirements of visible-near infrared(VNIR) high-precision observation of solar spectrum, a calibration method for a novel solar irradiance spectroradiometer based on spectrally-resolving technology was developed. The relative calibration based on standard lamp was carried out in 400 nm ~1 050 nm, and the Langley method was carried out in the band satisfying Beer-Lambert theorem, where after the solar irradiance spectroradiometer was traced to the solar spectral irradiance on the top of atmosphere (TOA) in the whole bands. The experiments carried out in Dunhuang and Hefei showed, the observation results were consistent with the MODTRAN4.0 theoretical model, and the deviations with CE318 were less than 5% in the four aerosol observation bands, which validated the rationality of the calibration method.