In this study, the channel flow is discussed by the Lattice Boltzmann Method (LBM) simulations. In the cases of channel with obstacles inside, the cylindrical pillars play the role of causing interruption within the fluid field, and hence change the direction of fluid flow. The recirculation region is formed behind the obstacles and influences the fluid passed through not only in the velocity field but also in the temperature field. Therefore, heat transfer is enhanced in local region. The field synergy principle is applied in the research to demonstrate that the increased interruption within the fluid increases the synergistic level between the velocity field and temperature gradient field.