Referring to limitation of the conventional spectral calibration in Ultraviolet-Visible (UV-VIS) wave band, a high spectral resolution calibration device was built for ultraviolet-visible spectrometer. It primarily consists of a stable 300 W xenon lamp, a Schwartzschild mirror, an echelle grating monochromator, and a collimator. The optical system of the monochromator was optimized by using ZEMAX optical design software. The apparatus design is described and analyzed, and results show that it satisfies the design requirements of the monochromator. Spectral region from 270 nm to 500 nm can be scanned, and its spectral resolution is less than 0.05 nm with wavelength accuracy less than 0.05 nm.