A numerical technique for the homogenization of the thermal conductivity properties of woven composites using a two-level approach was developed. At the microscale level, the averaged thermal conductivity characteristics of a strand were calculated based on the given properties of carbon fibers and epoxy matrix. At the macroscale level, a representative volume of the woven composite was homogenized, and components of the thermal conductivity tensor of equivalent homogeneous material were determined. In this case, the effective thermal conductivity characteristics of the strands found at the first level of homogenization were used. The finite element method was applied for the solution of stationary heat conduction problems. For a composite based on plain weave fabric, economical representative volumes were constructed, and systems of boundary conditions required at each level of modeling were formulated. Numerical results were presented for different packing densities of fibers in strands.