Abstract: To investigate the rupture mechanism of the M_S 6.8 earthquake in Dingri, Xizang, we inverted the rupture process of the mainshock using teleseismic waveforms and refined the hypocenter locations of the aftershock sequence through the double-difference relocation method. The results show that the rupture process lasted approximately 22 seconds, with unilateral propagation to the north along the causative fault. The rupture extended for about 60 km, and the maximum slip reached 2.4 meters, located roughly 30 km north of the mainshock, forming a co-seismic surface rupture zone consistent with field geological survey results. The aftershock sequence exhibited a characteristic north-south distribution, which can be roughly divided into three clusters. The earthquake distribution in the southern and central clusters indicates a complex fault structure and suggests the co-seismic activation of multiple secondary faults. Early aftershocks were concentrated in the low-slip regions at the periphery of the main rupture zone, complementary to the high-slip areas (>1.5 m), consistent with the “stress shadow” effect. Subsequent aftershocks migrated southward and formed conjugate clusters trending NE-SW and NW-SE, revealing a multi-directional stress adjustment process during the post-seismic stage. These findings suggest that the regional tectonic stress field plays a significant role in controlling the rupture process, and that the aftershock distribution is closely related to post-rupture stress redistribution and regional tectonics.