InterferometricSyntheticApertureRadar(InSAR)allowsproductionofhighresolutionDEManddetectionofsmallearthmotionsusingmultiplepassSARdatasetsobtainedbyremotesensingsatellite.ButthewholeprocesshasnotyetreachedsufficientrobustnesstowarrantautomatedDEMproductionascommonlyproducedbystereovisionwithopticalimages.TheautomaticalgorithmforprecisionregistrationisoneofthebottlenecksinInSARdataprocessing.Inthispaper,anautomaticapproachwithmulti-stepimagematchingalgorithmispresented.Allproceduresareautomaticallyimplemented.TheexperimentiscarriedoutsuccessfullywithSIR-C/L-bandInSARdata.Thetriangularpiecewiserectificationisalsoadvancedinreducinglocaldistortionbetweentheimagesandprocessingthelargesceneimage.Theprimaryresulthasprospectintheprecisionregistrationfortherepeat-trackInSARdataandrevealsthepotentialofthepresentedautomaticstrategy.