Abstract: Detection of moisture content in oil products is an important link to guarantee the safety of aviation fuel. Thus, the oil-water interface measurement of aviation fuel and accurate drainage of water in an automatic way is the inevitable trend for development of aviation fuel storage and management. By comprehensively researching the existing oil-water analysis technology, an oil-water interface measuring method based on the capacitance detection technology was put forward with consideration given to the storage characteristics of aviation kerosene, so as to accurately measure the oil-water interface at the bottom of the aviation fuel tank, and in combination with the process flow and the site control technologies, to realize the automatic drainage of water at the bottom of the tank. The results show that, the measuring method can greatly improve the accuracy of oil-water interface measurement and the automation of water drainage, further to reduce the operation cost resulted from the labors and excessive discharge of kerosene and to improve the information management of oil depot.