According to IRD theory, we considered the infrared divergence response in the supe-rionic glasses, resulting from mang-body interactions caused by the presense of disorder. On the basis of studying a new relaxation mechanism, we revised the rate equation of anelasric strain, and then using Boltzmann superposition principle, the formula of ultrasonic attenuation with IRD is derived. From this, the power law dependence of ultrasonic attenuation on frequency α∝ωn at low temperature side and an apparent activaion energy EA+ are obtained. They are in agreement with experimental data for superionic glasses (Agl)x(Ag2O·nB2O3)1-x.