Abstract: In simulator training for nuclear power plant operators, simulator instructors set up multiple fault superimposed scenarios to improve operators' response and control capabilities to the transient state of the nuclear power plant. This paper conducts research on the working condition of islanding operation superimposed with GCT121VV fault shutdown in Qinshan nuclear power plant unit 2, and uses the CP660 full-scope simulator platform of Qinshan nuclear power plant unit 2 to carry out simulation experiments. It analyzes the impacts on the unit nuclear power, control rod position, final power setpoint, and steam generator water level under this working condition, and proposes control strategies to stabilize the unit state, deepen operators' understanding of the unit state under fault superimposed conditions, and improve their ability to analyze and judge faults.