Abstract: 【Purpose/significance】Since this century, major public health events (MPHEs) such as SARS and COVID-19 have oc⁃ curred frequently, endangering people's lives and property. The information related to MPHEs is complex and diverse, and the re⁃ sponse to MPHE is a multi-stage and multi-body collaborative decision-making process, which is an important element in the con⁃ struction of the national public health governance and epidemic prevention and control system.【Method/process】Under the overall national security concept, this paper integrates the Decision Making Laboratory Analysis Method (DEMATEL) and regret theory into the case reasoning process and proposes a collaborative decision-making method for MPHEs based on case reasoning, which provides methodological and technical means to support the construction of an emergency intelligence analysis and intelligent decision-making platform for MPHEs.【Result/conclusion】The results of the case study prove that the proposed method is effective in emergency decision-making, reflecting the influence of the psychological behavior of decision-makers, and improving the scientificity of emer⁃ gency management decisions for MPHEs.【Innovation/limitation】In the future, as the number of historical cases increases, the avail⁃ able case information in the emergency decision-making process of major public health events becomes more abundant, and better re⁃ sults may be obtained by considering multiple historical case information for decision-making.