On December 18, 2023, a M_S6.2 earthquake occurred in Jishishan County, Gansu Province, marking the largest earthquake recorded in the area since seismic observations began. To investigate the practical application of interferometry synthetic aperture radar(InSAR) technology in monitoring surface deformation in Jishishan County and its surrounding areas before and after the earthquake, 13 C-band Sentinel-1A SAR images covering the earthquake event and study area were utilized. D-InSAR and SBAS-InSAR techniques were employed to process the data, obtaining surface deformation information along the radar line of sight before and after the earthquake, and a comparative analysis of the deformation rates before and after the event was conducted. The results show that the monitoring results of the two techniques show a bulge phenomenon centered in Liugou Township (the epicenter), which gradually expands outward in an elliptical shape, and then evolves into irregular subsidence. The maximum line-in-line shape variables before and after the earthquake are 41 mm and 16 mm, respectively. The overall deformation of the whole region after the earthquake is relatively stable, which is consistent with the relevant data. The D-InSAR and SBAS-InSAR technologies can be used to monitor the long-term surface deformation process and abnormal conditions before and after earthquakes, and provide effective support for quickly obtaining the distribution range of coseismic geological disasters and guiding post-earthquake emergency rescue and post-disaster recovery and reconstruction.