Abstract: This paper firstly analyzes the key behaviors of operators in the interface management tasks by using Systematic Human Error Reduction and Prediction Approach (SHERPA), and then uses INTERACT9, a kind of software, to analyze the video of the operator operation in the interface management tasks on the full range simulator of one nuclear power plant in China. After the statistical analysis of the data collected by INTERACT9, the four general characteristics of the tasks are obtained: a. The most frequent operations are conducted on the menu bar, the monitoring target and the parameter interface by operators in the first and secondary loop; b.The operators prefer to enter different system interfaces through the menu bar; c. The interface management tasks under normal conditions and accident conditions for the operators in the primary loop are generally the same, but the interface management tasks under normal conditions are significantly less than that under accident conditions for the operators in the secondary loop; d. Under normal conditions, the interface management tasks for the operators in the primary loop are significantly more than that in the secondary loop. Under accident conditions, the interface management tasks for the operators in the primary loop are equivalent to that in the secondary loop.