In order to make a preliminary exploration of the unity of the study of soil-rock mixture under different basic materials and different scales，the electrochemical impedance spectroscopy method was used to study the soil-rock mixture composed of ideal materials. Through the macroscopical adjustment of the three materials indexes of the rock-soil mixture system of water content，soil-rock ratio，and particle size，the rules of the electrochemical impedance spectroscopy results were obtained. Based on the high-frequency extremum of the electrochemical impedance spectroscopy(EIS)，its regularity was described and further studied. Thus，a preliminary mapping was made between the electron passability at the micro-scale and the material indexes at the macro-scale. A series of concepts and tools such as coupling degree，curve of the impedance¢s extremum(CIE)，optimal point of CIE were put forward. The basic effect of water content on the structure of soil-rock mixture was obtained，and the influence of soil-rock ratio is dominated by two factors. Especially with the orderly change of the particle size，its high-frequency extremum moved along curved path. These above research results have some reference value to the study of the structural characteristics of soil-rock mixture.