Abstract: In view of two approximate continuities in mutual correlation image matching process: the image gray level distribution continuity and the mutual correlation coefficient value in the parameter space continuity,the iterative algorithm is proposed to calculate the mutual correlation from hierarchical key points and the search space mark principle.By hierarchical key points algorithm,mutual correlation coefficients of the matching images can be iterative calculated from the important points to unimportant points in the images hierarchically,and the correlation coefficient can be obtained at any time with satisfactory precision.The search space mark principle enable us remove massive spots in parameter space impossible to match.The experiments show that the new algorithm can greatly enhance matching speed and achieve accurate matching results.