Since the existing control methods of DC magnetic bias problem rarely involve the combination of passive control equipment, parameter setting and comprehensive application of optimization algorithm, this paper studies this problem. Firstly, single-tuned filter and second-order high-pass filter are used to control the DC bias phenomenon of a single transformer, and then two different methods are used to calculate the parameters, and then the filter equipment is combined. In order to properly solve the problem of where to install DC bias suppression equipment in local power grids, the grey wolf coupled cuckoo algorithm is introduced to set the objective function based on the problem. Ensure that the peak current at the neutral point does not exceed the limit value, and use the harmonic distortion rate of each station and the economic factors of equipment installation as the objective function to reasonably select the installation location of the equipment in the entire power grid. The final simulation results can prove that the research in this paper has a good effect.