The effect of metal-semiconductor Zn-ZnO core–shell structure on dielectric properties of polyvinylidene fluoride (PVDF) composites was investigated. Zn-ZnO fillers were obtained by the heat-treatment of raw Zn particles under air. The enhanced dielectric constant of Zn-ZnO/PVDF composites results from the duplex interfacial polarizations induced by metal-semiconductor interface and semiconductor–insulator interface. The dielectric loss is still low because of the presence of ZnO semiconductor shell between Zn metal core and insulator PVDF matrix. Furthermore, the dielectric performance of as-prepared composites could be further optimized through adjusting the thickness of semiconductor shell.