Abstract: By analyzing the disadvantages of the traditional image mosaic algorithms,an automatic image mosaic algorithm based on local entropy is proposed.At first it uses Harris corner detector to extract the feature points from two images.The algorithm is based on local entropy of precise positioning advantage,the least local entropy and corners' constraint relations are used to match interest points.PERANSANC algorithm is used to reject false matches and compute homography matrix.The Triangle Function is used to get smoothing seamless mosaic image.The result shows that the algorithm is robust and effective.