Abstract: In the new-type power system, harmonic issues have become increasingly prominent, emerging as a key factor affecting power quality and system stability. Filter transformers play a central role in harmonic management. To further optimize the performance of filter compensation devices and improve filtering efficiency, this paper proposes the design idea and implementation scheme for the zero-impedance filter winding of filter transformers. By precisely regulating the key parameters of the transformer, this scheme realizes the optimization of the "zero impedance" characteristic of the filter winding. The research confirms that optimizing the structural parameters of the winding is the core path and key link to achieve the design goal of "zero-impedance" filter winding. The research results provide a more economical and efficient technical solution for system harmonic management.