In recent years, wind power has been rapidly developed in Guizhou,and many wind farms are far from load centers and locate in the ends of regional grids which weaken the stability of the regional grids. The paper focuses on a large-scale wind turbines tripping accident which previously occurred in a regional power grid of Guizhou province. Wind farms models and power grid models are built with actual parameters on DIgSILENT/PowerFactory platform, and the accident inversion simulations are carried out. Based on the inversion simulation results, the process of large-scale wind turbines tripping accidents are studied. The effects of wind turbine tripping on voltage and frequency stability of power grid are also analyzed. At last, the strategies which can improve the ability of low/high voltage ride through of wind turbine and avoid large-scale wind turbines tripping, are analyzed based on the regional power grid. Simulation results show the effectiveness and limitation of the strategies, which can provide a reference for similar cases in other regional power grid.