In order to satisfy the application requirements of real-time spectral imaging for moving targets, we design a static, snapshot imaging spectrometer based on a CDP(crossed dispersion prism). The spectral imaging principle is studied, and an optical system of broadband spectral imaging spectrometer is designed according to this principle. Imaging spectrometer consists of a CDP, an imaging lens and a detector, with ±2°field of view, spectral coverage from 0.6 to 5.0 μm, The results show that this instrument has a better ability to detect spectral from 0.6 to 5.0 μm while the average spectral resolution is 20 nm. The technology for dynamic target real-time spectral imaging provides a new technical way. It has a great potential for detecting, locating and identifying unknown energetic events in real-time.