The anisotropy of thermoelectric properties and microstructures in Bi2Te2.7Se0.3 fabricated by repressing (hot deformation) is investigated. The initial particle and grain size decreased with high-energy ball milling time, which affected the degree of grain orientation during the hot deformation process. To achieve high-performance thermoelectric properties, the anisotropic TE properties are optimized with the control of the degree of grain orientation, carrier concentration and temperature-dependent transport properties. By optimizing synthesis processes, we achieved a highly anisotropic figure of merit (ZT), with peak ZT values of 0.7 and 1.05 at 423 K, in the out of plane and in-plane directions, respectively. The in-plane ZT of the hot deformation sample was enhanced by 24% compared with that of the as-pressed sample (ZT = 0.85) due to reduced electrical resistivity and thermal conductivity, which was attributed to the significant anisotropy in grain orientation.