In this paper,the three-dimensional coseismic deformation field of Changning M s 6.0 earthquake in Yibin,Sichuan Province on June 17,2019 was obtained by using the differential interferogram images of ascending and descending Sentinel-1A satellite.Then,the coseismic de-formation data was taken as the constraint condition, and the inversion results based on the Okada elastic half-space dislocation model show that the seismogenic fault conforms to the characteristics of strike slip and thrust. The fault rupture scale of the M _S 6.0 earthquake is about 15 km ×20 km; the dip and rake angles are 44.37^°and 56.42^°, respectively; the focal depth is about 10.2 km, and the moment magnitude is M _w 5.8. Finally, the SBAS-InSAR technique was used to obtain the cumulative deformation of the study region from April 5 to August 3, 2019. The results show that the near-field deformation fluctuation of this region is small before the earthquake, and the cumulative deformation increases after the earthquake. The reason may be that the distribution of aftershocks makes the surface change in an unstable state. Through a comparison with the existing research literature and the analysis of the fault structure in the study area, this study inferred that the Changning earthquake is caused by the sliding of seismogenic fault. The upper edge of the sliding surface is close to the ground surface, and the secondary fault activity caused by the mainshock triggers frequent strong aftershocks in a short time.