This paper presents the design and analysis of dewatering systems for the foundation pits of urban substations in the context of smart grids. It highlights the necessity of efficient dewatering systems to ensure construction safety, improve efficiency, and protect the surrounding environment. The study focuses on the design of light well dewatering and open trenches with collection wells, evaluating their impact on the excavation process and the surrounding environment. Numerical analysis results demonstrate that light well dewatering effectively reduces water levels within the pit, ensuring safe and efficient excavation. The findings provide technical support for smart grid construction and foundation pit dewatering projects under similar geological conditions.