Abstract: The extremely difficult area has the characteristics of extremely rugged terrain, complex geographical environment and sparse permanent scatterers. Therefore, an improved SBAS-InSAR technology is designed to monitor the surface deformation. In this paper, the candidate permanent scatterers are obtained from the coherence, amplitude dispersion index and deformation rate, and then the final permanent scatterers are selected by optical images, which are introduced into the SBAS-InSAR calculation process as orbit refining control points, and finally the surface deformation monitoring in the study area is completed. By comparing and analyzing the conventional PS-InSAR technology and SBAS-InSAR technology, the technology has good application value in extremely difficult areas.