Objective To construct an operational indicator system for infectious disease monitoring and early warning, and provide data support and decision-making basis for monitoring and early warning. Methods A preli-minary indicator framework was constructed through literature analysis and expert interviews, and expert consultation was conducted using the Delphi method. A total of 30 experts were selected. The score of the importance of indicators based on the consultation results was calculated, and the weight was determined. Results The response rates of expert consultation questionnaires from two rounds were both 100%, with expert authority coefficients (reliability coefficient) being 0.87 and 0.88 for the first and second rounds, respectively. Kendall’s W coefficients ranged from 0.137 to 0.424, with statistically significant differences (all P<0.001). Coefficients of variation for all indicators were <0.25, indicating that expert opinions tend to be consistent and the results were authoritative and reliable. The finally constructed indicator system encompassed 4 first-level, 25 second-level, and 68 third-level indicators. Conclusion The operational indicator system for infectious disease monitoring and early warning developed in this study can provide a basis for the practice of infectious disease monitoring and early warning as well as related scientific decision-making.