Abstract: In this paper, we present an edge-local image mosaic algorithm based-on SIFT feature.construct a local affine edge-based mosaic algorithm for reducing the cumulative error for stitching multiple images, and we gradually decay affine transformation in the mosaic process, make the mosaic image decreasing the distortion with over affine transformation.For the better analysis from visual about the process of change of feature points in image mosaic, this paper presents a skeleton graph algorithm based on feature points, skeleton graph can intuitive analyze the mosaic algorithms, this method can be widely used in the testing process of the image mosaic algorithm.