Abstract: Focus on the unsatisfactory matching results which caused by the line fragmentation, occlusion and interference factors. An improved line matching algorithm based on the similarity of straight line overlap degree for close-range images is proposed in this paper. Firstly, use the SIFT matching algorithm to extract the corresponding points; secondly, use the corresponding points to calculate the affine transformation; thirdly, map the left image line to the right image through affine transformation, calculate the overlap of the matching lines, and optimize the matching results; finally, determine if they are the same line. Experiment results show that the algorithm is simple and effectively avoids complicated calculations. Also it has better robustness which means the applicability for different types of close-range images data.