Abstract: Steel structure building is an important part of prefabricated building, but the severance of steel structure deepening design and production process design affects the development of its intelligent production and construction. To realize the integrated application of steel structure welding design information and process information in the same 3D model, this paper analyzes the limitation of Tekla Structures software in expressing welding information and proposes the solution of constructing an integrated design-process model by modifying the objects.inp file to design the user-defined attribute window and integrating the process information into the steel structure deepening design model. Taking portal steel frame column base node as an example, this study establishes the welding process information input window to verify the feasibility of this method to build an integrated model.