Abstract: Considering the redundant feature points,high computational complexity,low robustness in image mosaic method based on scale invariant feature transform (SIFT) algorithm,a steady and fast image mosaic algorithm is proposed.This paper introduces Harris corner operator into the process of extracting feature points based on SIFT algorithm.The improved SIFT algorithm picks out Harris corners from the SIFT feature points when checking them in multi-scale space,chooses feature points that stand for image information.PERANSANC algorithm is used to compute the homography matrix between the two images.Then the detected corners are regarded as moving objects in the images,located accurately by the KLT track algorithm and the homography matrix is refined.The experiments verify the algorithm’s efficiency and robustness.