A high precision absolute radiance radiometer based on the ultroviolet (UV) standard detector is made up according to the complexity of the normal measurement of the spectral radiometric characteristics of the integrating sphere and the disadvantage of the huge uncertainty of the standard lamp in UV band. Calibration in three wavelengths is done so as to correct the curve of the aperture′s spectral radiance of the integrating sphere in 250~400 nm bands. Also the stability of the output, the uniformity of the aperture and the Lambert′s cosine characteristic of the integrating sphere are measured. The combined standard uncertainty in 280, 313 and 352 nm is 3.2%, 3.0% and 3.0% for the spectral radiance calibration and 1.7%, 1.6% and 1.6% for the stability of the output、the uniformity of the aperture and the Lambert′s cosine characteristic of the integrating sphere. Uncertainty analysis shows that research based on the absolute radiance radiometer is convenient, feasibility and has a higher precision in contrast to the traditional research of spectral radiance characteristics.