Abstract: In response to the dismantling requirements of the reactor pressure vessel head of Unit 1 of Qinshan Nuclear Power Plant, a head cutting process was designed based on a self-designed laser cutting device and a large component automatic cutting device. A three-dimensional virtual cutting simulation method was proposed and combined with the self-developed “Dragon Simulation” three-dimensional simulation engine; virtual cutting simulation verification was carried out on the head of the pressure vessel of Unit 1 of Qinshan Nuclear Power Plant in a three-dimensional simulation environment.