This study investigates the regulatory mechanism of trace Fe on the electromagnetic wave (EMW) absorption properties of graphene-based materials, specifically focusing on the Fe/reduced graphene oxide (RGO) composite. The research introduces a carrier injection strategy by designing Fe/RGO heterogeneous interfacial materials to fully utilize the dielectric dispersion properties of graphene. The EMW absorption mechanisms include enhanced conductance loss, dipole polarization, and interfacial polarization. The Fe/RGO composite demonstrates outstanding reflection loss (−53.38 dB at 2.45 mm) and broadband wave absorption (7.52 GHz with only 2 wt% filling), outperforming single-component graphene. The study combines off-axis electron holography, simulation calculations, and carrier transport experiments to demonstrate the carrier injection behavior from Fe to graphene, leading to increased interfacial and dipole polarization and conductance loss. The results show that regulating the dielectric properties of graphene by adding trace metals not only ensures good impedance matching but also fully exploits the dielectric loss ability of graphene at low filler content, offering an efficient way for designing lightweight absorbers. The study also explores the electronic transport mechanism of Fe/graphene, revealing that Fe enhances the polarization behavior and dielectric loss ability of RGO. The EMW absorption performance of Fe/RGO composites is analyzed, showing that the addition of Fe significantly improves the absorption performance, with Fe/RGO-2 achieving a reflection loss of −53.38 dB and an effective absorption bandwidth of 7.52 GHz. The study highlights the importance of interfacial electronic interactions in enhancing the dielectric properties of RGO and achieving excellent EMW absorption performance. The findings provide new insights into the relationship between the electrical and dielectric properties of graphene and offer a promising approach for designing high-performance graphene-based absorption materials.This study investigates the regulatory mechanism of trace Fe on the electromagnetic wave (EMW) absorption properties of graphene-based materials, specifically focusing on the Fe/reduced graphene oxide (RGO) composite. The research introduces a carrier injection strategy by designing Fe/RGO heterogeneous interfacial materials to fully utilize the dielectric dispersion properties of graphene. The EMW absorption mechanisms include enhanced conductance loss, dipole polarization, and interfacial polarization. The Fe/RGO composite demonstrates outstanding reflection loss (−53.38 dB at 2.45 mm) and broadband wave absorption (7.52 GHz with only 2 wt% filling), outperforming single-component graphene. The study combines off-axis electron holography, simulation calculations, and carrier transport experiments to demonstrate the carrier injection behavior from Fe to graphene, leading to increased interfacial and dipole polarization and conductance loss. The results show that regulating the dielectric properties of graphene by adding trace metals not only ensures good impedance matching but also fully exploits the dielectric loss ability of graphene at low filler content, offering an efficient way for designing lightweight absorbers. The study also explores the electronic transport mechanism of Fe/graphene, revealing that Fe enhances the polarization behavior and dielectric loss ability of RGO. The EMW absorption performance of Fe/RGO composites is analyzed, showing that the addition of Fe significantly improves the absorption performance, with Fe/RGO-2 achieving a reflection loss of −53.38 dB and an effective absorption bandwidth of 7.52 GHz. The study highlights the importance of interfacial electronic interactions in enhancing the dielectric properties of RGO and achieving excellent EMW absorption performance. The findings provide new insights into the relationship between the electrical and dielectric properties of graphene and offer a promising approach for designing high-performance graphene-based absorption materials.