Abstract: Aiming at the problem existing in the secondary cable insulation monitoring, a method of leakage current data analysis based on cable insulation monitoring is proposed by analyzing the methods of leakage current data collection, storage and analysis, and a leakage current data acquisition and analysis tool based on computer is developed. The application results show that the method and tool is effective to solve the problems such as the difficulty of directly obtaining the original leakage current data and the lack of effective evaluation means of leakage current sensor. A set of convenient and efficient automatic extraction, conversion and analysis system of leakage current data is made, which provide some technical reference for the analysis of secondary cable insulation monitoring data and sensor testing of the substations.