On January 14,2015,the Jinkouhe M_S5.0 earthquake occurred at the juncture of northern Sichuan and Sichuan Basin,where only several earthquakes had been recorded. Based on the digital waveform date and seismic phase report of Sichuan Regional Digital Seismic Network,the Jinkouhe earthquake sequence was relocated by double-difference method,and focal mechanisms of the sequence of 9 earthquakes with M_L ≥ 2.0 were calculated by employing the CAP method and HASH method. The coulomb stress in the region was also calculated by coulomb3.The result indicates that:① The Jinkouhe M_S5.0 earthquake was located at(103.18°E,29.32°N).The focal depth was about 16.6km,which was slightly deeper than the depth obtained using waveform inversion (12km). The aftershock sequence was evenly distributed in the intersection of NNW trending Tianquan-Yingjing fault and NE trending Xihe-Meigu fault,which were aligned tending to the NE directions. ② Focal mechanism solution result indicated that the M_L ≥ 2.0 aftershocks were mainly dip-thrusting,the nodal plane parameters of the main event were as follows:nodal plane Ⅰ is strike=350°,dip=46°,rake=107°,and nodal plane Ⅱ was strike=146°,dip=47°,and rake=73°. ③ The result of coulomb stress indicated that the aftershocks mainly occurred in the area where the coulomb stress increased. According to comprehensive analysis,we inferred that the NNW-striking Tianquan-Yingjing fault was the seismogenic fault of the main shock,and the nodal plane Ⅰ of NE dip point out the occurrence of the fault,the M5.0 main shock immediately triggered the NE-directed Xihe-Meigu fault,and then triggered many aftershocks.