Abstract: A new initial match algorithm using six-point groups and area ratio is proposed.Its main idea is to constitute triangulated irregular network(TIN) and six-point groups by point sets,search the pairs of homonymous six-point groups by area ratio and affine transform relations,and then establish initial transform equations between two characteristic point sets by polynomial.According to the counterpart points,the sub-image can be corrected using small panel correction.Experimental results show that it can match two images automatically without manpower intervention and other auxiliary information.