The steel roof system of China Medical City( Taizhou) Exhibition Center is complex. In view of the difficulties of engineering construction,the BIM structure model for the long-span steel structure was built,and the BIM structure model of the installation facility was constructed. And the visualization features of BIM technology had been applied to carry out real-time monitoring of the deformation of the construction facilities, timely warning for abnormal situation and rectification,so as to ensure the saf...