Spectrometer is one of the most important optical instruments. A digital spectrum analysis system based on change coupled device (CCD) is set up. The optical system, CCD, data acquisition board and spectrum analysis software are integrated to implement the digitization, automation, miniaturization and portability of the system. Spectrum analysis software is developed to realize the function of collecting, analyzing, displaying, peak-seeking, calibration and storage of spectral signal. Spectrum analysis library (SAL) is designed, which greatly simplifies the procedure of software development and increases software protability. The digital spectrometer is calibrated by standard mercury lamp and the software is verified by the laser test. The system is mainly used for remote-site real-time detection of military targets, at the same time, it can be considered for civil use. The experimental results show that the digital spectrum analyzer has a good accuracy and repeatability.