Abstract: In response to the significant discrepancy between the measured cathodic protection data and the actual potential of aviation oil pipeline in an airport, it is found that there is a close correlation between the accuracy of cathodic protection potential measurement and the impedance of measuring equipment through field tests, laboratory simulation experiments and scientific theoretical research. When the impedance value of the measuring device is small, the voltage division of the cathodic protection potential signal, the attenuation of the actual cathodic protection potential and obvious measurement errors will be caused. Furthermore, environmental conditions such as temperature and humidity can induce degradation in the resistance of the potential transmitter, thereby contributing to measurement deviations and reducing the accuracy of measured data.