In this paper, a 220kV substation occurred in a 220kV oil immersed inverted current transformer failure were analyzed. Based on the principle and characteristics of the current transformer, this paper analyzes and judges the cause of the accident using the structure, characteristic analysis, accident site investigation and test diagnosis of the oil immersed inverted vertical current transformer to determine the influence of rainfall and the state of oil leakage The lower the amount of evaluation criteria for the accident the main reason. At the same time, this paper puts forward the management methods and technical measures to avoid such accidents, and provides a reference for the analysis of the same type of accidents. Introduction In recent years, an oil immersed inverted current transformers is widely used in China because of its structure and characteristics. However, it will inevitably appear fault in operation. Therefore, the cause of failure must be studied and analyzed, taking appropriate precautions. The Structure of Oil Immersed Inverted Current Transformer Figure 1 Oil immersed inverted current transformer structure diagram 1-The head of transformer;2Bellows expansion indicator;3Oil filling screw(sealed); 4Metal bellows expander;5High voltage insulation;6Secondary winding and core; 7-Primary winding;8Cast aluminum head shell;9-Rings;10Porcelain insulator; 11Terminal box;12-Secondary terminals;13Oil drain screw(sealed); 14The lifting shaft;15Earth terminal 2nd International Conference on Automation, Mechanical Control and Computational Engineering (AMCCE 2017) Copyright © 2017, the Authors. Published by Atlantis Press. This is an open access article under the CC BY-NC license (http://creativecommons.org/licenses/by-nc/4.0/). Advances in Engineering Research, volume 118