The leakage of an enclosure structure will cause abnormal changes in the seepage flow field, which in turn can lead to the deformation of the enclosure structure and affect the surrounding geotechnical body. In this paper, a fiber-optic temperature measurement system is used to detect the location of the seepage points in a station of the Qingdao subway during open pit excavation, and the abnormal variation of the seepage field caused by the seepage points is obtained by numerical calculation and field measurement. Then, numerical simulation is performed to analyze the effects of seepage field anomalies on the deformation of the enclosure structure and surface settlement. It is found that the seepage flow caused by the leakage point has a significant influence on the surface settlement and the deformation of the enclosure structure. With the increase of excavation depth, the deformation of the enclosure structure increases and the maximum deformation position shifts downward. The deformation of the enclosure structure decreases when the leakage point exists. The surface volume also increases gradually with the excavation, and the maximum surface settlement position shifts outward significantly. The settlement range becomes larger when the leakage point exists.