<p>In order to develop elastomer composite with high thermal conductivity based on polyester (PET) fabric and further prolong the service life and improve service safety, modified PET fabric was prepared. Initially, different content of carbon black was added into butadiene latex and phenolic resin to prepare complex emulsion. Then, the emulsion was coated on the fabric by dipping and rolling technique. The results showed that carbon black possessed excellent stability and could be dispersed in butadiene latex uniformly. Meanwhile, the viscosity of the complex emulsion was low. The absolute value of zeta potential exhibited that carbon black could promote the reaction of complex emulsion. In addition, the tensile properties and thermal conductivity were both improved after adding carbon black. When adding 5.3 wt% carbon black, the tensile strength of carbon black modified emulsion film could reach 6.57&#xa0;MPa and the thermal conductivity could reach 3.16W/(m∙K). As a result, the thermal conductivity of 5.3 wt% carbon black modified emulsion-coated PET composite reached 3.43 W/(m∙K), which was 38.31% higher than that of pure emulsion modified PET composite. The results showed that carbon black was an excellent and low-cost nano-filler, which could be used to improve the thermal conductivity of PET-related elastomer composite.</p>