The Luding M_S6.8 earthquake occurred on Moxi Fault of the Xianshuihe fault zone on September 5,2022. In this paper we built a three-dimensional model of the Xianshuihe fault based on fault geometry,physical and mechanical fault parameters and fault slip rate. Using Virtual Quake earthquake simulator,we conducted massive calculation to carry out the Xianshuihe fault quasi-static numerical simulation. The independent simulations results of seven branch faults of the Xianshuihe fault are found to be in conformance with the biggest historical earthquakes and earthquake recurrence cycles. We found that bending of fault plane may result in uniform stress distribution,and the stress may accumulate at the bend location,where is easy to trigger earthquakes. The rupture segmentation reduces the seismic frequency and creates conditions for strong earthquakes. During the 10000 years of united simulation along the Xianshuihe fault,there are 33 M≥7.0 earthquakes with the biggest one of M7.6. The interaction among the earthquakes in the fault system and the complicated fault geometry influence the earthquake migration. The simulation results of two M≥7.0 earthquakes along the Daofu fault within 40 years and two M≥7.0 earthquakes along the north part of the Qianning fault within 5.8 years is consistent to historical earthquake records.