Based on ASAR data covering Bam earthquake, D-InSAR method is used to obtain LOS direction coseismic deformation field. Aiming at the problems of incoherence and terrain error in deformation field, support vector regression method (SVR) is used to recover the incoherence, and a function model is established based on the latitude and longitude of deformation field and DEM to remove the residual terrain error, so as to obtain the complete deformation field. The three dimensional deformation field of Bam earthquake is obtained by a method of combining multiple InSAR technologies. The results show that the SVR method can recover the decoherence area well, and the seismogenic structure of Bam earthquake is a nearly north-south fault, which is dominated by right-handed strike slip movement.