The invention relates to a testing technique for testing transmission characteristics of spectral radiation, particularly to a testing device for testing transmission characteristics of ultraviolet-vacuum ultraviolet spectral radiation. The testing device comprises a monochrometer, a standard light source, a vacuum container, a photomultiplier tube disposed in the vacuum container and fixed at one side of a rotary table, a cryogenic pump and a molecular pump respectively communicated with the cavity of the vacuum container via two gate valves, a dry vacuum pump communicated with the cavity pipeline of the vacuum container, and a cryogenic unit communicated with the vacuum container via a pipeline, wherein a flange interface is provided at one end of the vacuum container and used for alternatively connecting with the monochrometer or standard light source; the movement platform capable of performing translational movement with respect to the vertical direction of the axial line of the interface is disposed in the vacuum container, and the rotary table is disposed on the movement platform. The invention can be used for high-precision calibration of the spectral radiation brightness and the spectral irradiance responsibility of the entire machine of an ultraviolet spectra remote sensing instrument; and can be used for testing the spectral responsibility of an ultraviolet detector and testing the spectral transmission characteristics of an ultraviolet optical element.