Abstract: In order to study the risk of major and serious flood accident in coal mine, based on the theory of accident causation, the risk coupling analysis of four factors including personnel, equipment, environment and management in coal mine flood accident was carried out, combined with the statistics of major and serious flood accident in coal mine from 2000 to 2017 in China, N-K model was used to calculate the accident risk values of each coupling situation. The results show that personnel factor is most active and management factor is most sensitive; the risk value of four-factor coupling is the greatest among muti-factor coupling situations; management and environmental factors have the greatest impact on the occurrence of accident; decoupling the environment from management can significantly reduce the risk of an accident. The research results can provide reference for the prevention and treatment of major and serious flood accident in domestic coal mine.