The invention relates to an AC filter cut-off method of a DC rectifier station. The method includes a first working condition state signal, a second working condition state signal and a third working condition state signal of the DC bipolar of the DC rectifier station; acquiring different cut-off instruction signals according to different working condition state signals, calculating the different cut-off instruction signals to obtain the target signal for cutting off the AC filter of the DC rectifier station, thereby realizing the cutting off of the AC filter of the DC filter station. In this scheme, when the DC bipolar of the DC rectifier station is in different working conditions, the different cut-off instruction signals can be generated, the time sequence of the cut-off instruction signals is corresponding to the different working conditions, and the time sequence of the final target signal is also corresponding to the working conditions, the target signal is used to cut off the AC filter of the DC rectifier station, the problem of harmonic overvoltage caused by improper AC filter cut-off time sequence under the different work conditions can be prevented, and the equipment safety of a DC power transmission system can be effectively guaranteed.