Machining, manufacturing and on-site assembly will lead to micro-defects on the outer surface of aircraft hydraulic pipelines. Fluid-solid coupling vibration of pipelines will lead to micro-defects gradually transforming into cracks or even expanding into penetrating cracks, which will lead to leakage failure of pipelines. Therefore, the dynamic characteristics of aircraft hydraulic pipeline with circumferential non-penetrating cracks were studied, the fluid-solid coupling vibration equation of aircraft hydraulic pipeline and the modal function of fixed-support constraint pipeline at both ends were established, and the modal function of cracked pipeline was constructed on this basis. Galerkin method was used to solve the fluid-solid coupling problem of pipeline. By discretizing the vibration equation, the influence of crack location and crack circumference angle on pipeline dynamic characteristics was obtained. Finally, considering that pipeline crack would expand into a penetrating crack under cyclic impact, the leakage failure of aircraft hydraulic pipeline under cyclic pressure impact was simulated. By wavelet transform and negative pressure wave method, pipeline leakage location was detected and located. Finally, the pipeline leakage fault experiment was carried out to verify the accuracy of the detection method.