In order to prevent the mosaic line from passing through the visually significant features when the orthophoto map is mosaic, and damage the integrity of the features in the image. In this paper, a mosaic line extraction method for orthophoto images is proposed, which combines edge information optimization LSC and improved A-star algorithm. Firstly, the super-pixel segmentation theory of linear spectral clustering algorithm (LSC) is introduced into the mosaic line extraction algorithm of orthophoto images. The classical linear spectral clustering algorithm is optimized by using edge intensity factor to effectively use the spectral information and edge information in orthophoto images. Secondly, the improved linear spectral clustering algorithm is applied to the overlapping areas of two orthophoto images to obtain the boundary feature maps of various ground objects; Then, the edge irregularity and isolated noise in the boundary feature map are removed by mathematical morphology; Finally, the improved A-star algorithm is used to search the shortest path in the boundary map to quickly obtain the optimal image mosaic line. This method is compared with related methods by using the aerial orthophoto Image of a real UAV, The results show that the proposed method can extract mosaic lines efficiently and with high quality. It effectively bypasses the visual salient features and meets the application requirements of the actual orthophoto map making.