Urban water security problems such as water scarcity, water pollution, and flood disasters have restricted the sustainable development of cities. In order to scientifically evaluate the urban water security situation, this study combined the DPSIR (driver, pressure, state, impact, response) model and HEVD (the hazard of disaster-causing factors, the vulnerability of disaster-affected bodies, the instability of the disaster-pregnant environment, and population loss) model to propose a new conceptual framework for DPEBLR (driver, pressure, environment, insecurity-affected body, loss, response). Based on this conceptual framework, 35 indicators were selected to establish an urban water security evaluation index system. In order to solve the problem of randomness and fuzziness of the boundary values of urban water security classification levels, the cloud matter element model was applied. Chongqing was used as an example for verification, and the results showed that the water security status of Chongqing City improved from 2011 (Ⅴ) to 2019 (Ⅱ). This indicates that the water ecology restoration project, centralized water source protection project, centralized water supply project, water-saving society transformation, and flood and drought prevention system construction project implemented in Chongqing has achieved significant results. However, Chongqing still faces the problem that the construction of an urban flood control system cannot meet the speed of urban development. The government should slow down the urbanization and allow the urban flood control system to be ready before the area is occupied. In addition, the awareness of water conservation for industrial use in Chongqing has been formed, and citizens’ awareness of water conservation for domestic use should be enhanced in the future.