Abstract: The design, manufacture and application of improved laser-infrared imaging system for leaky inspection of SF6 were presented. On the basis of previous laser-infrared imaging systems for leaky inspection of SF6, advanced pattern processing techniques were used to improve the patterns of laser irradiation and infrared imaging, including eliminating the background pictures and then enhancing the dynamic images of the SF6 leakages. Utilizing the digital signal processing, small and weak leakages of SF6 could be clearly displayed in the real-time video, which prominently increases the detective sensitivity, which could be less than 10-3 cm2/s. Therefore, the improved laser imaging system was an effective instrument for inspecting SF6 leakage to guarantee safe operations of electric power instruments and networks, and also to decrease environmental pollution induced by SF6 leakages.