Abstract: A novel active hyperspectral imaging system in which a digital filter is specially designed as a creative component is developed for calculating the spectral cube and spectral response of an object. Based on the refit of a general WDF Wadsworth monochromator, the system enhances the exit flux and improves the optical intensity radiated on the object when the light incident keeps a constant. Furthermore, the optical narrowband filter is replaced by a digital filter. The hyperspectral imaging system resolves the problem of the system with a number of optical filters which can not be adjusted continuously, and it has lower cost than other filters. Meanwhile, the system is easy to implement, wavelength tunable, and band variable. According to the characters of the system and image gathering, the calculation method is supplied and the inaccuracy is less than 2 nm. The spectral cube and response of green leaves are successfully achieved, and the system is suitable for the spectral measurements with a small view in laboratory.