The Development of computerized tools is essential for enhancing analytical techniques related to fire protection safety of nuclear power plants and for supporting regulatory activities. In this paper, a fire safe shutdown analysis method of a nuclear power plant using fault tree analysis is proposed. The proposed method was established by preparing area-specific fault trees reflecting fire-affected components and cables in each fire area, and by quantifying the fault trees. Application of this method enables systematic generation and quantification of the fault trees for each fire area, thereby facilitating the assessment of whether safe shutdown conditions are met based on the quantified results. The proposed method will be implemented in a computer program of a New Fire Safe Shutdown Analysis and utilized in the review and validation of existing analysis results.