Abstract: A coal-rock interface identification scheme based on Hough transform was proposed according to characteristic of coal-rock image, namely boundary between coal seam and rock seam is significant and linear. Coal-rock image is pre-processed firstly by denoising and enhancing. Then isolated points on coal-rock edge are removed as well as false edges. Finally, Hough transform is used to identify coal-rock interface. Experimental result shows that the scheme can detect coal-rock boundary fast and correctly.