We established an angle-resolved spectral measurement system based on coaxial rotation arms to construct the optical characterization on plasmonic structures. Two arms slew around the sample stage surface to achieve directional stimulation and collection; and a standard rod through two slewing bearings was used as the constraint and allowed radial relative movement between the pivot arm and electric turntable, which ensured the coaxial rotation to get accurate angle information. The spectrophotometer was calibrated by back-propagation neural network algorithm to ensure accurate wavelength information of angle-resolved spectrum. This system had altitude angle from 7.9°to 89°, and the angular resolution is 0.1°. Experiments on one-dimensional periodic gold grating and two-dimensional periodic structure on gold film demonstrated the capacity of the system in angle-resolved spectroscopic characterization for plasmonic samples in different environment, at different altitude angles and different azimuth angles.