Abstract: The property of behavior of nuclear power plant operators is analyzed by the unified modeling language,based on which a method of workflow modeling for behavior of operators is proposed.This work-flow model can be used to analyze the reliability of operators.Workflow model not only describes the proper-ties and constraints of behavior of operators exactly and visually,but also analyzes the behavior of operators from many different angles,such as workload,resource utility,control flow optimization,and etc.Two typical events are used to describe the proposed modeling method.