Abstract: Reactive power of wind farms significantly impacts the power grid.Current standards specify requirements for the dynamic reactive power response time and duration of wind farms, yet they do not address the reactive power dynamic response performance of wind turbines.To address this gap, this article attempts to propose indicators for quantitatively evaluating the dynamic response performance of wind turbines, including reactive power response time, capabi-lity, and support capability.The effectiveness of the proposed wind turbine reactive power support capability index is verified using PSD-BPA simulation and analysis of actual wind farm voltage and reactive power operation data.The index value positively correlates with the transient voltage stability limit of wind turbines.The smaller the voltage drop depth of the wind turbine, the longer the duration of reactive power output and the higher the index value, indicating a stronger reactive power support capability of the wind turbine.