Abstract: In order to analyze the behavior characteristics of the nuclear power plant crew when dealing with severe accidents, focusing on the study for the particularity of Severe Accident Management Guideline, combined with field investigation and interviews with operator and emergency technical support personnel, this paper establishes a crew decision-making model in the process of severe accident mitigation, and identifies the key influence factors of decision makers and executors, which laid a firm foundation for the studies of human reliability analysis method in severe accidents.