The study process of the satellite-borne solar ultraviolet spectrometer is briefly introduced. The optical and mechanical structures of the ultraviolet spectrometer (SBUS) are introduced. SBUS is a compact, high-precision satellite-borne spectral radiometer. It can measure 160~400 nm solar ultraviolet-spectral irradiance under solar work modes. The calculation method and uncertainty factors of the measured ultraviolet spectral irradiance are analyzed. The measurement uncertainty analysis shows that the total uncertainty of the measured ultraviolet spectral irradiance is ±6.4% at 160~250 nm and ±5.2% at 250~400 nm. The data of solar ultraviolet spectral irradiance obtained by SBUS agree with the internationally published data with the deviation within ±5%.