The moderate-strong (M ≥ 5, since 1976; or M ≥ 6.5, overall) earthquakes of the north and south trending (NS-trending) faults and their adjacent in the southern Qinghai-Tibet Plateau has prominent spatial concentration distribution characteristics. However, research on the relationship between southern Tibet faults is limited. Hence, this study used a two-dimensional viscoelastic nite element model to simulate crustal movement in southern Tibet based on 1991-2015 GPS velocity data. The current deformation eld, tectonic stress eld, fault slip, and stress accumulation rate distribution were obtained to determine the relationship between fault activity and earthquake distribution. The results showed that the research area was simultaneously affected by NE-trending compression and uneven EW-trending tensile force, and crustal deformation exhibited simultaneous NS-trending compression and EW-trending stretching. The EW-and NWW-trending faults around the research area and the internal NS-trending faults differed in their mechanical properties and movement modes. NS faults were primarily subjected to extension stress with normal motion. Remarkable differences were appeared between different fault segments, controlling of distribution of moderate-strong earthquakes, and types of earthquake ruptures. The concentrated distribution of moderate-strong (M ≥ 5, since 1976; or M ≥ 6.5, overall) earthquakes on the NStrending normal fault and its vicinity depended largely on the high slip rate, strong tensile stress and geometric strike of the fault segment. This study is helpful to fully understand the differences in normal fault activity in southern Tibet, and is also the basis for seismic risk assessment.