Abstract: To address the problem of insufficient frequency perception accuracy caused by active power coupling interference on frequency information mapped by DC voltage in communication-free active frequency regulation of offshore wind power systems transmitted via flexible DC transmission, this paper proposes a communication-free active frequency support control strategy. Firstly, a dynamic analytical model is constructed to quantitatively reveal the inherent coupling mechanism between active power input fluctuations and DC voltage deviations, and a voltage-power coupling analysis framework is established. Secondly, a communication-free active frequency support strategy based on real-time power-voltage observation and feedforward compensation is proposed. Finally, a simulation model of the communication-free active frequency regulation system for offshore wind power via flexible DC transmission is built in Matlab/Simulink for simulation verification. The simulation results show that the proposed strategy can effectively suppress the interference of power transmission variations on frequency signals and markedly improve the accuracy of offshore-side perception for onshore grid frequency. The proposed strategy enhances the system’s active frequency support capability while ensuring stable dynamic response, which provides a feasible solution for communication-free frequency regulation of offshore wind power.