Polymer conductive composites have attracted significant attention in materials science due to customizable properties, corrosion resistance, lightweight nature, excellent processability, and low cost, which have increasingly extensive applications in electronics, aerospace, and energy devices. However, the relatively low electrical conductivity of polymer composites with carbon-based nanofillers restricts their use in highly conductive applications. Over the past few decades, considerable research has been directed towards enhancing the electrical conductivity of these composites. This review highlights recent advancements in the development of highly conductive polymer composites, focusing on strategies such as segregated conductive networks, multiphase blending, and pre-constructed 3D conductive networks. The benefits and current challenges of these methods are discussed. Additionally, the paper summarizes the practical applications of highly conductive polymer composites with carbon-based nanofillers in various high-conductivity fields. This review offers valuable insights for the preparation of next-generation conductive polymer composites tailored for diverse high-conductivity applications.Highlights Comprehensive strategies for enhancing conductivity in CPCs are thoroughly reviewed. Explores applications in fuel cell plates, EMI shielding, and conductive adhesives. Future research trends and challenges are critically discussed.