Objectives To explore the risk quantitative evaluation indicators and model for protecting the centralized water supply safety in the regional large-scale events in order to find the key chains for ensuring the centralized water supply, and to offer scientific evidence for the securing health safety of drinking water in the regional large-scale events.

Methods Delphi expert consultation method was adapted to establish the indicator systems of the risk evaluation of the centralized water supply safety in the regional large-scale events, and the weights of indicators to be identified. Furthermore, the comprehensive index method was used to establish the linear risk evaluation model for evaluating the centralized water supply risk for the centralized water supply health security in the regional large-scale events.

Results The average length of service of the thirty-two experts was (21.56±6.81) years. The response rates of the two-round consultation from the experts were both 100%, the average coefficient of experts^, authorities were both 0.91±0.07, and Kendall's coefficient were 0.661(χ²=507.628, P < 0.01), 0.822(χ²=631.242, P < 0.01), and opinions among experts tend to be consistent. Five first-class indicators, twenty second-class indicators for risk evaluating the centralized water supply health security, which could seriously influence the regional large-scale events, were determined. And the weights of the indicators were established. The average weights of hygiene management, water sources management, architectural design and sanitary facilities, hygiene management during the production and water quality management were 1.94, 2.16, 1.11, 2.09 and 2.70, respectively. Moreover, the linear risk evaluation model was established.

Conclusions The establishment of the risk quantitative evaluation model for the centralized water supply health security in the regional large-scale events provides scientific evidence and technical support for security public health of the regional large-scale events, which was worthy of wide spread.