Abstract: Noise filtering is a critical step in the InSAR interferogram processing. This article proposes a novel InSAR interferogram filtering method based on spin filtering with a thorough consideration of the directional features of interferograms. The method is proved effective in the elimination of the influence that residues have on phase unwrapping and keeps phase unaffected at the same time. Its effectiveness is exemplified by the results of both simulated InSAR data and real InSAR data processing.