Abstract: Dielectric constant, temperature resistance and halogen-containing of halogen-free high-temperature resistance and low-dielectric constant functional materials, such as inorganic non-metals, organic polymer, and composite materials, are reviewed. Relevant methods of process improvement are also introduced. Meanwhile, research and development progress of cable materials and products for conventional signal transmission in China is briefly analyzed. Furthermore, current domestic standard of cable materials (foamed cables) for conventional signal transmission is listed, and its limitations are analyzed, which can provide valuable references and insights for the research and development application of halogen-free high-temperature resistant and low-dielectric constant functional materials in special signal transmission cables.