Abstract: Proceeding from the CCD image sensing and digital image processing technologies which should be improved for the spherical-aberration automeasurement system based on Hartmann method, the target discrimination and search algorithms of the Hartmann diaphragm image in the image-reflectionarea, and the center superposition algorithm for the spot distance measurement of the Hartmann diaphragm image are proposed to solve the problems for accurately searching the two-dimensional image targets in onedimensional image memorizer and then implementing some calculations of the relative targets. The center of Hartmann diaphragm image is solved by utilizing the centers of mass of all the light spots, and then the algorithm for the center superposition of the mass center distance is confirmed by the center symmetry of the diaphragm image. The result indicates that the times of computation are cut down and the computing complexity of the algorithm is reduced.