Abstract: In this paper, the dynamic of a large-scale wind turbine system in earthquake was researched. Based on Eurocode 8, the random ground motion swas generated as acceleration time history, the use of dynamic inflow theory for aerodynamic load calculation. Based on multi-body system dynamics, a wind turbine rotor-tower dynamic model was built, and the system dynamics analysis of seismic effects was researched through the model. The results show that the loads caused by seismic loads are greater than wind loads. The analysis data, compared with the wind power software authority GH Bladed, show that the model can calculate the loads of a large scale wind turbine in earthquake.