Abstract: Surface energy is one of the important thermodynamic parameters reflecting the surface characteristics of coal. Adsorption method is commonly used to calculate the coal surface energy. Contradictory conclusions exist in describing coal adsorption with surface energy calculated by this method according to previous research results. There exists a circular reasoning problem logically in describing coal adsorption with surface energy calculation results based on adsorption experiments. Therefore, this method should not be used to reflect the adsorption of coal. Circular reasoning problem must be avoided to explain coal adsorption mechanism with surface energy. Other actually experimental measurement could be tried, but it is difficult to implement. There is no significance in explaining adsorption characteristics of coal to methane with surface energy. Bring into disciplines such as quantum chemistry and studying the interaction between microscopic coal macromolecular structure and methane molecular in depth are essential to explore the nature of coal methane adsorption.