Abstract: External event Human Reliability Analysis (HRA) is different from the HRA in the internal event level PSA. Therefore, based on the investigation of the development history and method defects of the HRA of external events, the technical standards of the reliability analysis of external events at home and abroad are studied, and the human events in the seismic PSA of a nuclear power plant are taken as the research object. The method study illustrates the difference between the seismic HRA and the internal events HRA, the process of the seismic human response, and the analysis method of the human reliability under the earthquake, so that the analysis results obtained are closer to the actual situation of the external event, and it can provide a technical basis for the development of external event PSA.