The invention relates to a DC frequency limiter control method, which comprises the following steps: obtaining a frequency f of an isolated power grid; judging whether the frequency f of the isolated power grid exceeds a limit range of a frequency limiter or not; determining a reactive power Q which is absorbed from an AC system by a rectifier station; determining a reactive power variation rate K absorbed from the AC system by the rectifier station; and controlling the frequency limiter according to f and K. The method provided by the invention can ensure that a frequency limit controller can develop the advantages of being flexible and quick to adjust and high in accuracy when an AC or a DC of a sending-end system is in power imbalance disturbance, and play a positive role in stabilizing the frequency after system disturbance; meanwhile, the risk of a voltage drop of an AC/DC system after an AC system failure is lowered; and the transient voltage stability of the DC sending-end isolated power grid is improved.