Abstract: To address the issues of untimely data feedback and excessive reliance on secondary development of native software for visualization in excavation monitoring, BIM lightweight technology and IoT devices are employed to achieve online visualization of excavation monitoring information, enabling real-time monitoring and early warning during the construction process of excavation. Firstly, the BIM model of excavation is established using Autodesk Revit software, and lightweight technology is applied to display it on a web platform. Secondly, IoT devices are utilized to collect data on various monitoring indicators of excavation, and the data is transmitted to the server in real-time, allowing the front-end webpage to retrieve monitoring data from the database as needed. Thirdly, the monitoring data corresponding to the monitoring points are associated with POI within the engine functionality, achieving a binding between the monitoring data and POIs. Lastly, monitoring thresholds for different safety states are set, and when the actual value exceeds the alarm threshold, the system automatically triggers an alarm and pushes the alarm information to relevant construction managers. This research not only enhances the accuracy and real-time nature of excavation monitoring but also provides timely early warning information to construction managers, which is beneficial to reduce construction risk and ensure the safety and reliability of the project.