Abstract: Tianjin water engineering dispatching model assembly platform is one of the core contents of the construction of Tianjin flood dispatching and emergency command platform system. The platform mainly implements standardized packaging and unified management of 35 water sector models and 45 sets of modeling files in 6 categories that are suitable for business scenarios such as flood dispatching, urban waterlogging, and water resources management in Tianjin City. It supports the free assembly of computing solutions according to the requirements of computing areas and scenarios, realizes the unified management and construction framework of algorithms, models and solutions, and provides business system modules for use in the form of services. The digital twin system for existing and future planning provides a unified computing power and algorithm center to support the business of flood and drought disaster prevention and water resource management and allocation in Tianjin City.