The team proposes an innovative rapid inundation model, the Hybrid Inundation Model (HIM), to simulate urban flooding. The model combines the advantages of Cellular Automata (CA) and Digital Elevation Model (DEM), and it can produce results without the need for powerful computational resources such as high-speed computers and parallel computing. Therefore, this model has the advantages of real-time computation and provides time-varying inundation results in a short time. The team has completed the initial development of the model and tested it against the EA benchmark test cases, which are the most commonly used in the UK to verify the correctness of 2D flood models. The results confirm that the HIM model has promising potential for future applications.