Abstract: In the excavation and civil construction of subway station foundation pits, manual measurement is mainly used for pit monitoring. This traditional monitoring method has many problems: limited equipment movement in the on-site construction space; redundant manpower and material resources mobilization; manual monitoring data is not intuitive enough. In order to optimize the monitoring of subway station foundation pits and achieve automated detection, the development and application technology of a BIM-based automated monitoring system for subway station civil construction is proposed. This technology establishes various modules such as surface settlement monitoring in Revit models, and imports data into the monitoring platform to achieve real-time display of data on the platform, thus completing the establishment of an automated monitoring system for subway station foundation pits and achieving automatic data collection. In the East Extension Project of Guangzhou Metro Line 3, as well as the synchronous implementation of the general contracting project, the application of this technology has shown the advantages of high frequency, good timeliness, high stability, and reliable data. It provides real-time and accurate monitoring for construction safety and enhances risk prevention and safety assurance for underground civil engineering construction.