Abstract:A MS7.0 earthquake occurred in Jiuzhaigou, Sichuan, on August 8, 2017. In order to improve the precision of the InSAR coseismic deformation field of the earthquake and to clarify the structural morphology and formation mechanism of the seismogenic fault, the coherence coefficient of the deformation zone is statistically analyzed to determine the coherence threshold. Atmospheric correction of the deformation field is performed by GACOS(general atmospheric correction on-line service). Then, the basic shape of the seismogenic fault is confirmed according to aftershock distribution and geological background. Finally, the slip distribution of the seismogenic fault is inverted based on the Okada elastic half-space dislocation model. The corrected InSAR coseismic deformation field shows that the maximum sink is 25 cm and the maximum lift is 10 cm in LOS, which are respectively located in the northwest and the southeast of the epicenter. The long axis of deformation is in NE direction and the main deformation zone is located on the west of the seismogenic fault. The inversion results show that the RMSE of the corrected InSAR deformation field is smaller than that before correction. The maximum slip amount is 0.9 m, the average slip angle is -0.5° and the moment magnitude is MW6.5. The rupture is mainly concentrated in the range of 1 ~ 20 km underground. The results are consistent with the results of USGS and GCMT. The consequences indicate that using GACOS to correct the InSAR coseismic deformation field of Jiuzhaigou has some effect on improving the accuracy of the deformation field, but the inversion result of fault slip distribution is not significantly different than before correction. The attributes of the seismogenic fault are basically consistent with the properties of the northern segment of the Huya fault. Combined with the results of the aftershock repositioning, it can be inferred that the seismogenic fault is the northern extension of the Huya fault. The earthquake event is the result of the collision between the southeast torsion of Bayankala block and the South China block. The difference distribution of viscous lower crust is the main reason for the change of the slope angle of the Huya fault.