In the construction process of deep and large foundation pits, groundwater is the key factor that affects the stability of deep and large foundation pits. If it is not handled properly, it is easy to cause safety accidents in the construction of deep and large foundation pits. At present, the dewatering design and technology of large-scale foundation pit engineering in water- rich geology are strict, and the application is less, so it is necessary to carry out in-depth research. Based on the engineering example of the deep foundation pit of Kunming Rail Transit Railway North Station, combined with the hydrogeological characteristics around the station, this paper designs the dewatering scheme of dewatering wells in the pit and arranging standby wells outside the pit. The dewatering scheme of the foundation pit is calculated and simulated by VisualModflow numerical simulation software. The calculation results show that the dewatering scheme can meet the requirements of foundation pit dewatering, and the surrounding surface subsidence caused by foundation pit dewatering is within the allowable safe range. At the same time, it is further verified by the on-site monitoring data that during the excavation of the foundation pit of the North Railway Station, the change of groundwater level is relatively stable, and the surrounding surface settlement meets the requirements of the code. The dewatering scheme has reference and guiding significance for the dewatering design of similar deep and large foundation pits.