To clarify the complex relationship between multiple factors in the urban water system and provide help for the system to solve urban water problems, a theoretical framework of nexus model to describe the interaction and feedback among water-economic society-ecological environment in urban water system was proposed based on water system theory and relevant studies on urban water system. A new model controlled by positive feedback loops for economic development and negative feedback loops for sustainability in the evolution of urban water system was established. A nexus model of urban water system that simulated the interrelationship of water-economic society-ecological environment was constructed. Taking Wuhan City as an example, the built nexus model of urban water system was applied. A simulation model of the mutual feedback effect of water-economic society-ecological environment elements was built by adopting historical statistical data from 2001 to 2017 and predicted the urban development trajectory of Wuhan City. The validity of the model was verified compared with the long-term planning of Wuhan City in 2030, which indicated that the urban water system model could reveal the multi-elements coupling driving mechanism of water-economic society-ecological environment and reflected the good expectation of the coordinated development of ecological environment and economic society under the guidance of two major factors of water-saving technology and green development related policies.