In order to effectively identify the factors that affect the risk of major public health emergencies, an evaluation index system, including four first-level indicators and eighteen second-level indicators, was firstly constructed from four aspects: event characteristics, prevention capabilities, control capabilities, and recovery capabilities. Then, the fuzzy DEMATEL method was employed to identify the critical factors of major public health emergencies. Lastly, the critical factors were identified and thus the feasibility of the method verified via case studies which analyze the influence, cause, and centrality of factors affecting major public health emergencies.