The influence of dewatering and excavation on the ground settlement is analyzed by means of numerical simulation, with the construction of the foundation pit of No. 3 bid section of Tianjin Railway Station Terminal as an example. It is concluded that the settlement induced by dewatering takes 90% of the total, while the adverse influence of excavation mainly takes the form of differential settlement. Therefore, the water seeping through the waterproofing curtain should be timely sealed and enough waling should be set up during construction. Analysis is also made on the simulation results on basis of the monitoring data and conclusion is drawn that the cutandcover topdown construction method is superior in terms of settlement control. Finally, an optimized construction scheme is proposed.