The purpose of building the Yangtze River for the Huaihe River Diversion Project is to improve water supply in the Henan and Anhui Provinces of China. Risk management is an important task in this project, which aims to ensure safe water supply. This paper presents the design of a risk management system for water diversion projects. The system is developed based on a microservice architecture and is divided into three parts: data layer, model platform, and business application. The data layer stores all the business data of the system and provides data services. The model platform is the core component of the system. It integrates models related to the risk management of water diversion projects, including risk identification, risk evaluation, and contingency plan-matching models. Each model is published separately as a micro-service, and the model calculation service is managed by a service registry center. Model calculations are primarily executed in the form of asynchronous calls. In this case study, we used the Henan section of the Yangtze River to the Huaihe River Diversion Project as an example to demonstrate the risk-management system. The system implemented an identification and control process for the four risk categories, providing assistance in ensuring the construction and operational safety of the diversion project.