In order to establish the correlation between engine lubricating oil and electro-chemical impedance spectroscopy (EIS) and to achieve oil degradation pattern recognition based on electro-chemical response, Mobil 1 FS 0W-30 engine oil was taken as the object. Based on the analysis of the mechanism of lubricating oil degradation, the experimental research was carried out on the electro-chemical response characteristics of typical degradation modes such as oxidation aging, moisture pollution, metal debris pollution, coal activated carbon pollution, fuel pollution and quartz powder pollution. Oil samples with different degradation modes were prepared, and the impedance mode values and phase differences of each degraded oil sample were analyzed through impedance spectrum frequency scanning test. An improved Randles model was used to analyze the impedance spectrum data, and electro-chemical parameters were extracted to characterize the performance state of oil. The research results indicate that the improved Randles model can be used to construct the electro-chemical fingerprints that describe the degradation state of lubricating oil performance. By monitoring the electro-chemical response characteristics, effective identification and differentiation of oil degradation patterns can be achieved, providing a powerful technical means for state based predictive maintenance.