Hydraulic system provides vital hydraulic energy for aircraft flight, and the pipeline vibration problem caused by pressure pulsation seriously affects the reliability of the hydraulic system. Conducting vibration and modal experiment of hydraulic pipeline is an important means to support hydraulic pipeline system design. However, thin-walled and slender hydraulic pipelines are often lightweight, their dynamic characteristics are easily affected by the additional mass of sensors during experiment. This article proposes a method to eliminate additional mass errors and correct the modal experiment results of pipelines. By establishing a elaborate and complete finite element model, Using additional mass elements to carry out numerical simulation, and finally the corrected modal parameters of pipelines are obtained. The data from the application case of the aircraft shows that this method can eliminate the influence of sensor mass on modal experiment, and the method provides references for finite element analysis of hydraulic pipelines and correction of modal experiment results of other thin-walled circular tube structures.