Abstract: To ensure the safety of a long-distance water diversion project, it is of great practical significance to study the simulation of its levee-breach flood routing and submergence process. This study has applied a network generation algorithm of growing-based Delaunay triangulation to development of a large-scale terrain model, and computed levee-breach flood with a 3D routing mathematical model. Levee-breach flood dynamic routing simulation in large city scene is realized by means of virtual reality computing technology, and levee-breach flood submergence routing 3D scene simulation system is developed based on virtual reality platform. This system, with a C/S structure, has functions of interactive 3D scene walkthrough and levee-breach flood routing simulation, featured with friendly interface, convenient use, precise data, and easy maintenance. Its application to a certain long-distance water diversion project has offered a simulation analysis and visual presentation of the flood routing useful for embankment project management and emergency decision.