Abstract: This paper introduces the structural characteristics of the aircraft fuel tanks, summarizes the causes and high-incidence areas of fuel leakage, and analyzes the feasibility of the existing internal and external leakage detection methods under the strength test environment. Finally, the implementation plan of the oil tank leakage repair work in strength test is formulated based on the ultrasonic and helium leak detection technology and on the combination of the results of test verification and field application.