We study the infrared absorption spectrum, the ultraviolet and visible reflection spectrum of the Agl(Cr2O3) mixed ionic conductor, as well as its micro shape and result of composition analysis obtained with TEM. It is found that there exists some diffrence between Agl(Cr2O3) maxed ionic conductor and the pure Agl, Cr2O3 with microcosmic meticulous structure.A new model of the electrical medium is developed. According to the micro shape, we expect that the reason of the change in the microcosmic meticulous is the deformation electrical polorzation has been deformed. The mechnism of the property change of the AgI(Cr2O3) mixed inonic conductor is discussed.