Based on a high-temperature blackbody and a double grating spectral comparison measurement system, the new primary standard apparatus of spectral irradiance was developed at the National Institute of Metrology (NIM) in the spectral wavelength from 230 to 2 550 nm. Stable 1 000 W tungsten halogen lamps are the secondary primary standard for spectral irradiance values. The temperature measurement of the high-temperature blackbodies was traced to the Pt-C and Re-C fixed-point blackbodies and checked against the WC-C fixed-point blackbody at 3 021 K. From 2017 to 2019, NIM participated in the new international comparison of spectral irradiance CCPR-K1 using the newly developed primary standard apparatus. An organized by BIPM. The comparison was piloted by VNIIOFI from Russia, with 12 laboratories participating. The comparison results show that, except for a few laboratories, the consistency of the participated laboratories is ±2.0%, ±1.0%, and ±2.0% at wavelengths of 250 to 290 nm, 300 to 1 300 nm, and 1 500 to 2 500 nm. The average relative deviation between NIM and the KCRV(key comparison reference values)is 0.13%, 0.28% and 0.15%, respectively, in the ultraviolet, visible, and near-infrared wavelengths. The whole wavelength from 250 to 2 500 nm, the average relative deviation between NIM and the KCRV is 0.17%. Compared with the average relative deviation of 0.9% in 2004, the measurement capability of spectral irradiancehas significantly improved.