【Objective】In order to study the displacement variation law of adjacent underground pipelines during the excavation of deep foundation pits.【Method】Based on a deep foundation pit project of Nanchang No.4 line, FLAC 3D software is used to simulate the whole process of dynamic construction of foundation pit, and the influence of different pipe materials, pipe diameter, buried depth and buried distance of internal support on pipeline displacement is analyzed. And the field deformation monitoring data are used for comparison and verification.【Result】The results show that the internal support plays a good role in limiting the displacement of the adjacent pipeline during the construction of the foundation pit. In the process of foundation pit excavation, the change of pipe material and pipe diameter mainly affects the settlement of pipeline.【Conclusion】The stiffness of different types of pipes is different. The greater the stiffness, the stronger the pipeline's ability to resist soil deformation. The settlement variation of the pipeline is negatively correlated with the variation of the pipe diameter. The buried depth of the pipeline has a significant effect on the horizontal displacement of the pipeline. The horizontal displacement of the pipeline increases first and then decreases with the increase of the buried depth, and reaches the maximum when the buried depth of the pipeline is close to 1/2 of the design depth of the foundation pit. Under the principle of following a single variable, there are differences in the influence range of displacement of pipelines with different buried distances. Compared with pipeline settlement, foundation pit excavation has a greater influence range on the horizontal displacement of adjacent pipelines.