Abstract: In the fine management of large and medium-sized sluice projects, the failure analysis of important small structures should be carried out in the design stage. Model building gets more and more complex. In order to facilitate model debugging, a hydraulic engineering design system based on 3D parametric model is proposed. The key technologies of parametric modeling are analyzed. Combing with Hongshanyao hydro-junction project, the parametric collaborative design method and the design scheme of using model to optimize earth balance and traffic road are discussed.