Thermoelectric materials can realize the mutual conversion between thermal energy and electrical energy and realize the reuse of thermal energy. Inorganic thermoelectric materials have excellent thermoelectric properties, but their poor processability and poor flexibility limit their development in the field of flexible materials. Poly(3,4- ethylenedioxythiophene) (PEDOT) has excellent thermoelectric properties and good flexibility, and its thermoelectric properties can be effectively improved by compounding with suitable inorganic materials. The research progress of PEDOT- based thermoelectric materials in recent years was reviewed. The preparation technology and thermoelectric properties of PEDOT modified with carbon nanomaterials, Bi- Te alloy, two- dimensional layered materials, nano- metals were introduced in detail. Finally, the methods to improve the thermoelectric properties of PEDOT composites were summarized.