This study presents a novel orthotropic 3D hybrid carbon network (VSCG) composite with polydimethylsiloxane (PDMS) for efficient bidirectional thermal conduction. The VSCG is fabricated by depositing vertically aligned carbon nanotubes (VACNTs) on a horizontally oriented graphene film (HOGF) and optimizing the interfacial interaction through annealing. The VSCG is then filled with PDMS to form VSCG/PDMS composites, which exhibit excellent 3D thermal conductive properties. The composites achieve in-plane and out-of-plane thermal conductivities of 113.61 and 24.37 W m⁻¹ K⁻¹, respectively. The high contact area of HOGF and the good compressibility of VACNTs improve the effective thermal conductivity by more than an order of magnitude. The VSCG/PDMS composite shows a 71.3% improvement in interfacial heat-transfer efficiency compared to a state-of-the-art thermal pad. This design offers a promising solution for high-performance thermal interface materials (TIMs) that meet the need for high thermal conductivity and low contact thermal resistance in interfacial heat-transfer processes.This study presents a novel orthotropic 3D hybrid carbon network (VSCG) composite with polydimethylsiloxane (PDMS) for efficient bidirectional thermal conduction. The VSCG is fabricated by depositing vertically aligned carbon nanotubes (VACNTs) on a horizontally oriented graphene film (HOGF) and optimizing the interfacial interaction through annealing. The VSCG is then filled with PDMS to form VSCG/PDMS composites, which exhibit excellent 3D thermal conductive properties. The composites achieve in-plane and out-of-plane thermal conductivities of 113.61 and 24.37 W m⁻¹ K⁻¹, respectively. The high contact area of HOGF and the good compressibility of VACNTs improve the effective thermal conductivity by more than an order of magnitude. The VSCG/PDMS composite shows a 71.3% improvement in interfacial heat-transfer efficiency compared to a state-of-the-art thermal pad. This design offers a promising solution for high-performance thermal interface materials (TIMs) that meet the need for high thermal conductivity and low contact thermal resistance in interfacial heat-transfer processes.