Abstract: This paper analyzed the process for the approval of the 24 backup documents during the feasibility study stage of Fang Jiashan nuclear power plant,and defined the 27 backup documents and derivative documents that should be obtained during feasibility study stage for nuclear power construction projects,and finally expound the 8 representative documents in detail.The analysis showed that the process for the approval of all the backup documents under the Approval System prolonged the project construction period.It recommended that the backup documents can be obtained from the nine departments,such as those involved in the economic planning,urban planning,land use planning and nuclear safety,as well as environmental protection.