Based on the characteristic of superionic glasses and the infrared divergence response theory, we studied the anelastic relaxation of amorphous superionic conductors. We consider that the ultrasonic attenuation of superionic glasses is due to the thermal active relaxation process of mobile superions bonded weakly to the glassy network and the accompanishing low energy excitation dissipation.The theory can explain the experimental characteristics which failed to be interpreted by previous theory with distributed relaxation times. Our predictions agree well with available experimental data.