Abstract: In bridge engineering, the cover beam is usually constructed in situ. Reasonable design of support is of great significance to ensure construction safety, and improve construction quality. Based on the Tailiu Highway Bridge, the support system for cast-in-place large cantilever cover beam is designed, and the three-dimensional finite element model of which is established by MIDAS Civil to analyze the force, deformation and stability. Results show that, considering different load combination conditions, the force, deformation and stability of each part of the support system meet the design requirements, indicating that the support system can meet the needs of bridge construction. In addition, the study also shows that the finite element numerical calculation can be effectively applied to the design and construction of related projects.