During the construction of large open sea ports,complex site conditions and numerous engineering vessels make it challenging to monitor the ships in real-time across a large area.We integrate building information modeling (BIM)+geographic information system(GIS) technology with ship positioning data of automatic identification system (AIS) to enable real-time 3D visualization of geographic information,dynamic ship tracking,and safety warnings.On the basis of a large-scale open sea port engineering,we carry out exploration and verification of two-dimensional,three-dimensional data display and spatial analysis,real-time monitoring and early warning of ships.The results show that BIM+GIS data fusion application in the ship monitoring significantly improves real-time monitoring capabilities of ships and provides valuable decision-making support for project management.