By utilizing the author's new theory and the Green function method, the eigenvalue of energy of the stationary soliton of protein is given. The binding energy of the soliton obtained with the theory is consistent with the experimental value. By taking further into account the random thermal modulation of the soliton, the absorption coefficient due to the soliton and the temperature dependence of the absorption strength of the red-shifted line at low temperature are given, too, which are in agreement with the experiment results.