Image registration is an important part of the image processing and computer vision. On the basis of analyzing two types of image registration, an automated image registration method was put forward to dealing with image registration with similar transformation. At first, Corner feature was extracted by the improved multi-scale Harris operator, next, the image edge detection was conducted by canny operator, corner's coarse matching may be realized based on correlation coefficient between the corner neighborhood on the edge image, and then fine matching can be achieved, two pairs of optimal matching corner were selected from matched corners as control points of affine transformation, thus, affine transformation model could be obtained, and the registered image was performed affine transformation in order to realizing image registration. Theoretically speaking, this method's advantage isn't subjected to change limitation of the displacement, rotation and scale between two images. Finally, the simulation experiment was performed to verify and analyze the algorithm characteristics; the results show that the automatic registration algorithm is correct and effective.