In response to the heterogeneity of decision information in emergency decision-making, and the decision information can be expressed as exact numbers, interval numbers, linguistic terms, intuitionistic fuzzy numbers, neutrosophic numbers, and trapezoidal fuzzy neutrosophic numbers, and considering the simple and easy use of case-based reasoning, an emergency decision-making method based on case-based reasoning in heterogeneous information environment is proposed. Firstly, the distance and similarity measure of heterogeneous data are introduced, and the heterogeneous information attribute weight is calculated based on the deviation maximization method. Then based on the comprehensive similarity measure, the case-based reasoning method is used to find the historical case that is the same or similar to the target case from the case base, so as to obtain an effective emergency plan and treatment measures for solving the current emergency. Finally, the feasibility and effectiveness of the decision-making method are verified by an emergency case, and the advantages of the method are illustrated by comparison with other methods.