Abstract: In order to reduce the complex image registration processing for the airborne dual-antenna interferometric Synthetic Aperture Radar (SAR) system, the extended wavenumber domainK auto-registration imaging algorithm in the range is presented. For the mismatch caused by the path difference of two antennas, this algorithm realizes the precision registration of interferometric image in the range by means of high degree polynomial approximation using scaling principle in course of the imaging processing. Finally, through the processing of the simulation data and the X bands real interferometric data, better interferograms are obtained and the validity of the algorithm presented in the paper is proved.