Abstract: The leakage of toxic or hazardous gases not only pollutes the environment, but also threatens people's lives and property safety. Many countries attach great importance to the rapid and effective gas leak detection technology and instrument development. To address this issue, a wide-band gas leak IR imaging detection system design was proposed, mainly including wide-band IR optical lens, the sub-band filters and switching device, wide-band Uncooled Focal Plane Array (UFPA) detector, video processing and system control circuit, which takes full advantage of the spectrally non-selective characteristic of the uncooled focal plane array detector. The system can sensitively detect and visualize a considerable number of different kinds of gases, which are not visible to the naked eyes, by using the IR image nonuniformity correction technology and Digital Detail Enhancement (DDE) technology. The resulting gas leak video easy to be observed for the human eye was provided. Many advantages are commendable, such as scanning a wide range simultaneously, locating the leaking source quickly, visualizing the gas plume intuitively, and so on.