Abstract: Under the background of centralized access of large-capacity high voltage direct current（HVDC） and high-ratio renewable energy resources, the problem of transient overvoltage has severely constrained the transmission capacity of HVDC and interconnection capacity of wind power, so it is quite necessary to conduct further studies on mechanism and influencing factors of transient overvoltage under large disturbance considering dynamic characteristics of wind generators. The study is conducted through both theoretical derivation and simulation analysis. Firstly, the theoretical equations for calculating transient voltage magnitude of converter station and wind generator side after AC/DC contingency are derived. Then, the mechanism and main influencing factors of transient overvoltage caused by AC/DC contingency are analyzed. Finally, the impact of different active/reactive power characteristics of wind generator during low voltage ride-through（LVRT） on transient overvoltage is analyzed combined with simulations. All the conclusions are verified through the simulation of practical case systems. The study results show that the LVRT characteristic of wind generator makes the wind farm be another"reactive power source"resulting in transient overvoltage besides the converter station, and the severer of the transient overvoltage will be caused by the smaller active power output and the larger reactive power output for the wind generator.