Abstract: In this study, the rupture process of the 2025 Dingri 6.8 magnitude earthquake in Xizang is rapidly determined based on a dense far-field seismic array, and the seismic intensity distribution and potential casualties are rapidly assessed based on the rupture process. First, the back-projection technique is used to obtain the spatial and temporal distribution characteristics of the energy release in the seismic source area, which reveals the dynamic evolution process of the rupture of the seismic source; then, combining the rupture process with the ground shaking parameter attenuation model based on the shortest distance from the fault, the spatial distribution of the seismic intensity is quickly calculated, and the scope and intensity of the disaster impact are clarified; based on this, the casualty assessment model is used to make a preliminary estimation on the casualties that may be caused by the earthquake. The results show that the rapid seismic intensity assessment method based on dense seismic array has high reliability and practical application value in the rapid assessment of post-earthquake disaster, which can provide important reference for government decision-making, emergency command and rescue deployment.