The application of digital SOP significantly changes the logic of operator handle the accident and the information display pattern in a main control room(MCR).This paper introduces the basic principle and the importance of the SOP of nuclear power plants. It describes the process that the operator using SOP to handle nuclear power plant incident in digital MCR. The negative effects of digital SOP on human error are identified by field research、behavior observation、simulator experiment and interviewing with operators in the aspects of the info...