Abstract: In recent years, the drop waterproof curtain(such as bottom-stopping diaphragm wall) has been widely used in deep foundation pit engineering in Wuhan. In many subway station foundation pit dewatering projects, the idea of the drop waterproof curtain stopping water+pipe well dewatering is adopted. However, in the construction of some transfer stations, the dewatering design of the new subway station does not consider thedrop waterproof curtain of the existing station, and the influence of the existing curtain on the new foundation pit may not be ignored. In this paper, Visual Modflow seepage numerical simulation software is used to study 8 working conditions established on the basis of typical first-grade terrace hydrogeological model of the Yangtze river, and the influence of existing curtain on the dewatering of new foundation pit is discussed. The results show that the maximum and minimum depth reduction in the new foundation pit tend to increase first and then decrease with the increase of the distance between the existing curtain and the new foundation pit.