Abstract: An arch dam consists of various curves and surfaces and the structure is complex. It is tedious and time-consuming to model it. In order to facilitate the rapid construction of the arch dam model, improve the modeling efficiency and reduce the duplication of effort in the modeling process, a new method is proposed for constructing the arch dam efficiently and quickly, which is based on CATIA secondary development of arch dam. Based on 3DEXPERIENCE platform, this method applies the object-oriented Python language to connect the CATIA module through the automated interface, and to conduct secondary development for the CATIA module, which takes advantage of the simplicity of Python code. The secondary development program can access the given EXCEL file to get the parameters of the arch dam, automatically create sketches, and then construct solid models to realize the function of building 3D shape in batch. It can reduce the trouble caused by the repetitive work of manual inputting parameters. Meanwhile, the work efficiency can also be improved. For this reason, there is great value of promotion for all. In addition, the 3DEXPERIENCE platform also has the technical characteristics of multi-stage modeling, superposition modeling and correlation modeling, which provides the basis for the realization of parallel collaborative design of models in the three-dimensional environment.