Proper foundation pit dewatering will have an important impact on the foundation pit excavation and the surrounding environment, so it is necessary to evaluate the foundation pit dewatering plan. In view of the problem of foundation pit dewatering at Yangzhong Jinyuan Times Shopping Center, MIDAS/GTS was utilized to study the effect of foundation pit dewatering. Firstly, according to the soil permeability coefficient provided in the geological survey report, in combination with the single well and double well pumping test results, the soil permeability coefficient and boundary functions required in the MIDAS/GTS were inverted. Then, with the parameters obtained from the inversion, a 3D analytical model of the foundation pit dewatering effect was established with consideration of the recharge effect of the backfilling well for simulation of the relationship between the water level drawdown and the time in the foundation pit any analysis and evaluation of the foundation pit dewatering effect, providing guide for earthwork excavation.