The single look complex image of synthetic aperture radar interferometry (InSAR) data includes four parts, all the parts of which will be used with the current InSAR data processing methods, which, however, is loaded with high-level decorrelation noise. In this paper, the InSAR data processing method proposed by the authors based on three part images are introduced comprehensively. The new technology includes image pair registration and the creation of interferograms. which is named contoured correlation interferometry (CCI). Firstly, the algorithm for the calculating of fringe orientations is introduced and improved. Secondly, the formulations of the image pair registration and the creation of interferograms are deduced with the correlation method in this paper, Simulative and practical experiments indicate that CCI method which needs only arbitrary three image parts from the four image parts of InSAR complex image pair to get interferogram without noise and blurring effect is a totally novel method to InSAR data processing, which also can save the time to data transferring and processing.