On September 19,2022,an M_W7.6 earthquake hit Michoacan,Mexico,where the Cocos plate subduct under the North American plate. To further study of the influence of the earthquake on the surrounding faults and follow-up earthquakes,and to analyze the background of earthquake preparation and occurrence of the earthquake sequence,by using the focal mechanisms of the mainshock and 2 M>5.0 aftershocks provided by USGS,and other foreign organizations,we firstly calculated the central focal mechanisms of the 3 earthquakes. Then,we calculated the Coulomb Failure Stress(CFS)change projecting on the fault plane and slip direction of the two strong aftershocks generated by the mainshock to analyze the triggering effect. In order to study the effect of the mainshock to adjacent area,we also calculated the displacement field and strain field generated by the mainshock. Finally,we estimated the stress field in source region by using 29 M_W≥4.9 earthquakes' focal mechanism collected from January 1,1976 to May 31,2022,and simulated the relative shear and normal stresses projected on various fault planes geometry under the estimated tectonic stress. The results show that:① According to the estimated central focal mechanisms,the mainshock and M6.8 aftershock are thrust type and the M5.8 aftershock is normal fault type.② The changes of CFS on the fault plane and slip direction of both M5.8 and M6.8 aftershocks exceeded the threshold of 0.01MPa,indicating that the two aftershock occurrences are triggered by the mainshock. ③ The compressional and extensional stress axes of the estimated stress in source region are NNE-SSW direction and vertical,respectively. The rupture of the earthquake sequence occurred nearly along the plane with maximum shear stress of the stress field,and released the accumulated stress caused by the tectonic movement to the utmost.