Abstract: Collapses of scaffold system account for a significant proportion in construction accidents so that safety analysis of scaffold system during construction received wide attention. However, the existing calculation methods have some deficiencies in 3D modeling and time-dependent description. This paper proposed a new safety analysis approach for scaffold system during construction by inducting 4D (4-Dimensional) technology and BIM (Building Information Model). The 4D Construction Safety Information Model, which provides complete information for dynamic connection between scaffold system and construction process information, is presented and established so that 3D models and structural analysis model of scaffold system can be generated rapidly and automatically, therefore the safety analysis process can be simplified greatly. This paper also demonstrates that safety analysis of scaffold system based on the 4D Construction Safety Information Model is feasible and practical through an application example.