The present invention relates to a magnetic-dielectric composite for a high-frequency antenna substrate, and a manufacturing method therefor, the composite comprising: a porous insulating dielectric substrate including an upper surface, a lower surface and lateral surfaces, and having a plurality of pores penetrating the upper surface and the lower surface; and soft ferrite nano-wires provided within the pores, wherein the soft ferrite nano-wires are encompassed by the insulating dielectric substrate so as to be separated from each other. The present invention controls a dielectric constant and can minimize eddy current loss by having a structure in which the soft ferrite nano-wires are provided within the pores of the insulating dielectric substrate and in which the soft ferrite nano-wires are encompassed by the insulating dielectric substrate so as to be separated from each other.