The PEDOT:PSS/Bi0.5Sb1.5Te3 powder was prepared by a solution phase process and grounding in liquid N2. Then the powder was densified by hot press. The polymer composite powder was reformed to polymer bulk. The XRD and FESEM were used to check the phase structure and microstructure. The electrical transport properties and thermal conductivity were measured. The results showed that 90 wt% Bi0.5Sb1.5Te3 with PEDOT: PSS specimen got the highest ZT value of 0.1 at 75 ℃ which is 40 times higher than that of pristine PEDOT: PSS specimen. The Seebeck coefficient was greatly improved with the increase of Bi0.5Sb1.5Te3. The continuous distribution of inorganic phases is the key to improve Seebeck coefficient of composites.