Based on geo-electric resistivity sensitivity coefficient,we take the four layer electrical structure of the Pingliang station as an example to analyze the distributions of sensitivity coefficients with the spacing and depth of the electrodes when the Schlumberger arrays are used in the resistivity measurement. The results show that for a fixed Schlumberger array,sensitivity coefficients display complex variations with the increase of electrode depth. By calculating the size of the sensitivity coefficient of each layer,we find that the well observations of the Pingliang station has good inhibition to surface and shallow interference of deep well geo-electric resistivity. The result of the analysis can be references for the selection of electrode depths and power supply distance in the implementation of deep well geo-electric resistivity observation for similar stations.