As municipal water supply pipes age, it becomes more and more critical to conduct a comprehensive risk assessment of them. Failure of a water supply pipe not only poses a serious threat to the normal and safe use of water by users, but also may lead to large-scale water wastage and economic losses. Traditional risk assessment methods are usually difficult to be practically applied due to their uncertainty. Therefore, the study of potential disaster risks of water supply pipelines has become the focus of great attention of governmental administrations and engineers. In order to protect the water safety of urban industrial production and residents, this paper proposes a risk assessment method for municipal water supply pipe network based on integrated fuzzy TOPSIS model and cloud inference, including risk factor analysis, risk status assessment and risk classification. Firstly, the risk indicator system is constructed using mathematical statistics and fuzzy TOPSIS analysis, and the corresponding risk indicator management program is developed. Subsequently, virtual cloud and fault tree analysis were applied to assess the risk status of water supply pipelines, and the final risk value was determined by triangular fuzzy number, structural entropy weight method and inverse cloud transformation algorithm. Finally, the risk assessment results of the water supply pipeline were clearly presented in the form of cloud reasoning. The study was conducted through a case study of a water supply pipeline in Shanghai, and the results showed that the central city was at risk level V, and the Pudong New Area and Jiading Area were at risk level IV. This is consistent with the actual situation, and verifies the effectiveness of the comprehensive fuzzy TOPSIS model and cloud inference analysis model. The findings of the study can provide technical support for the water supply network department to carry out network planning, design and operation management, which can help to ensure the safety of water supply in the city.