Abstract: Both 3D modeling and 2D drawing play important roles in BIM application.To fully utilize the advantages of Tekla software in reinforced concrete structures' BIM modeling to enhance the efficiency of frame bridge design, this paper introduces a frame bridge design instrument which is a secondary development product of Tekla with C# language.This instrument takes the text document of FUBS frame rebar calculation software as input data, and generates the 3D frame bridge reinforced concrete structure model and the 2D drawing along with engineering amount collection as results through the Tekla API interface.Meanwhile, this paper analyzes the develop flow and solution scheme of some key points within this design instrument.Through practice test, it is proven effective and efficient to design a frame bridge with this instrument.The develop process and scheme can be used as a reference for similar engineering applications.