Abstract: The preparation methods and intrinsic properties of bismuth telluride based alloy were briefly introduced. The multi-scale microstructure induced by hot deformation in bismuth telluride based alloy, including atom-scale intrinsic point defects, lattice line defects, nano-scale lattice distorted regions, micro-scale texture and grains were summarized. The effect of the multi-scale microstructure on thermoelectric properties of bismuth telluride based alloys was reviewed.