Abstract: In order to minimize the potential risks during the first time application of new erection technology of "flip in the air" and "inclined introduction" for the nuclear island primary loop equipment, this paper presents a new approach of simulation to be used for the nuclear island primary equipment erection, which can perform dynamic simulation and process verification for primary equipment erection, and carry out collision inspection and space quantification between the equipment and the civil work structure of nuclear island building, and has been successfully applied for the installation of nuclear island primary equipment such as reactor vessel and Pressurizer.