Abstract: Bi₂Te₃ powders were successfully synthesized by hydrothermal reaction, which were composited with carbon black (CB), and then the thermoelectric (TE) performance of Bi₂Te₃/CB composites was investigated. At the same time, TGA, SEM and XRD analysis methods were used to characterize the structure of Bi₂Te₃/CB composites and the relationship between microscopic structures and TE properties was researched intensively. It shows that the thermal conductivities of Bi₂Te₃/CB composites reduce sharply (from 0.5957 W/(m·K) to 0.0888 W/(m·K) at room temperature) because of doped with CB under the special structure design. However, the values of electrical and thermal conductivities of Bi₂Te₃/CB composites improve with the increase of Bi₂Te₃ weight fraction, and Seebeck coefficients increase first and then decrease. After sintering under 558℃ for 10 min, the figure of merit (Z_T) of Bi₂Te₃/CB composites with 88.9% Bi₂Te₃ is the best (Z_T=0.21) at room temperature. Although the Z_T value is much lower than the stand of TE material application, this topic investigation may provide new insights and optimization approach into the design and development of Bi₂Te₃ TE material for application, especially in terms of lower thermal conductivity of materials.