Abstract: Polyacrylonitrile-based carbon fibers (PAN-CF) are among the most widely used reinforcements in composite materials, characterized by their high specific strength and high specific modulus, which significantly enhance the mechanical properties of composites. Additionally, PAN-CF exhibits excellent axial thermal conductivity; however, its radial thermal conductivity is suboptimal. Coupled with the high thermal resistance of polymer matrices, this results in a substantial reduction in the out-of-plane thermal conductivity of composites. This study aims to enhance the radial thermal conductivity of PAN-CF and the out-of-plane thermal conductivity of carbon fiber composites through surface modification of PAN-CF. Initially, a three-dimensional hybrid network of nickel/carbon nanotubes (Ni/CNT) is electrodeposited onto the carbon fiber surface. Subsequently, vertically aligned graphene oxide (GO) is grafted onto CF@Ni/CNT through freeze-drying of a graphene oxide dispersion, followed by thermal reduction treatment to obtain CF@Ni/CNT@TRGO. At a filler content of 60vol%, the thermal conductivity of CF@Ni/CNT@TRGO-C reaches 1.98 W·(m·K)⁻¹, representing a 2.04-fold increase compared to PAN-CF-C. This study demonstrates that constructing continuous thermal conductive networks and vertical thermal conductive structures on the carbon fiber surface can significantly enhance the composites thermal conductivity, expanding the application of high-performance carbon fiber composites in the field of thermal management.