Abstract: In view of special monitoring environment of coal mine underground, algorithm of key frames extraction based on frame difference Euclidean distance was studied. For large redundancy of key frames of the algorithm, Canny algorithm was utilized to extract image edge, and edge matching was used to eliminate redundant key frames, so as to reduce redundancy. Theoretical analysis and simulation results show that the improved algorithm of key frames extraction can effectively reduce redundancy, and extract more reliable key frames.