The instrumentation and control system is digitized in nuclear power plants, which makes the operator's situation awareness error (SAE) more prominent. In order to identify the existing main SAE and carry out prevention and control, the SAE was classified first from the perspective of cognitive function in situational awareness. And then, the collected human factor events were analyzed by using the established SAE analysis method, in which data of 79 samples were obtained to identify the main SAE and causes. Based on the perspective of defense ...