Abstract: Purpose/Significance Due to the complexity and sudden nature of public health emergencies, it is important for decision makers to timely and accurately use effective emergency measures of similar public health emergencies in the past as a reference for decision-making. Design/Methodology This study proposes a method to make an emergency reference plan for public health emergencies based on case-based reasoning. First, a gene bank for public health emergency history that covers the entire phase of COVID-19 is established. Second, the interval is divided according to the characteristics of different numerical distribution of the index, and the repetition of the stages involved is calculated. Finally, the comprehensive similarity is calculated and an emergency reference plan is made. Findings/Conclusions Taking COVID-19 as an example, this paper establishes a gene bank for COVID-19 history, considers the distribution focus of different indexes, and finally matches the most practical emergency reference plan, thereby verifying the effectiveness of the method.