This paper takes the 74 major accident of coal mine during 2011-2020 as the research subjects in order to study the causal factors of major coal mine accidents， strengthen the safety management system and effectively avoid the occurrence of major coal mine accidents. Based on the characteristics of major coal mine accidents， this paper follows the analytic approach of “2-4” model accident cause chain to quantitatively calculate and analyze the occurrence frequency and proportion of the accident causal factors which reaches an conclusion for the causes of major accidents. Cause analytic models are constructed and Chi-squared test is used to analyze the correlation between the causes of major accidents at different levels before suggestions for major accident prevention measures are put forward. The results show that there are 20 groups of influencing factors between adjacent levels of major coal mine accidents， among which "insufficient awareness of safety， inadequate safety supervision， illegal and risky operation， and lack of production and construction qualification" are the most common causes for major coal mine accidents.