Classification method of coal mine gas explosion accident

This supplementary material records the principles, methods, concepts and the specific subcategories of coal mine gas explosion accident classification methods in the main text. The content is arranged as follows: The first section introduces the principles, methods, and concepts used to construct classification. The construction of classification relies on the constraints of principles, the guidance of methods, and the reuse of basic concepts; Section 2, 3 and 4 respectively introduce the subclasses of individual action causes, management system causes and other accident causes; Section 5 describes how to use the classification.