Abstract: Optical splitter is an important optical element in spectral imaging system. Among them, filter light splitting is a common and effective means of light splitting. A spectral imaging system based on angle-tuned narrowband filter splitting is proposed. By adjusting the Angle between the filter and the incident light, the central wavelength of the transmission spectrum is shifted, so as to realize spectral imaging in a specific wavelength range. The system mainly consists of an optical lens with an adjustable filter, an Angle tuning device, a CMOS camera and an upper stage mechanism. The field of view angle of the system is 17.5°, F# is 8, focal length is 26 mm, and total length is 200 mm. The MTF curve of each band is greater than 0.3 at 96 lp/mm, the distortion is controlled within 2%, and the spectral resolution is about 3 nm. After experimental testing and verification, the system can perform Angle tuning in the incidence Angle range of 0~46 degrees, which realizes the continuous light splitting function, and can capture the spectral image corresponding to any central wavelength in a certain spectral range.