With the construction of a large number of underground projects in water rich areas, the environmental problems of the changes of groundwater seepage conditions caused by underground engineering are becoming increasingly prominent. In this paper, the groundwater seepage when the subway station has not been built has been analyzed based on the one-dimensional seepage theory. Combined with the mirror image principle and superposition principle, meanwhile, the influence mechanism of the subway station on the groundwater seepage has been analyzed also, and the analytical formula of backwater height and groundwater flow due to the barrier effect of subway station was obtained. By the theoretical formula obtained in this paper, the backwater height and groundwater flow of of a subway station in Jinan nvcaused by the blocking effect of the station was analyzed, and the recommended value of anti floating water level considering the backwater was put forward. According to the analysis in this paper, the backwater height caused by the blocking effect of station structure is related to the influence radius of aquifer and hydraulic gradient. In practice, the possible backwater height after the completion of the subway station should be paid more attention to by the engineering personnel when encountering a strong permeable aquifer with a certain hydraulic gradient.