Abstract: A real-time monitoring technique for bottom plates corrosion and leakage of oil tank is put forward. In corrosion and leakage accidents of oil tank, the leakage of bottom plates takes in the highest proportion to other tank accidents. Based on an analysis on this kind of leakage and its detection method, the authors present a real-time monitoring technique for bottom plates corrosion and leakage of oil tank--the leakage detecting layer of tank foundation. The mechanism and principle of this monitoring technique, including its design, calculation and installation, are introduced.