<p>Fusion energy is regarded as a promising energy source due to its abundant fuel reserves, high energy efficiency, and reduced radioactive waste compared to fission. However, risks such as radioactive leakage, extreme operational conditions, and hazardous materials (e.g., cryogens, magnets) necessitate thorough safety assessments. Some countries have begun to develop their own fusion experimental devices to gain an advantage in the future energy distribution. Although fusion reactors have their inherent safety, there is still a risk of radioactive leakage that threatens the environment and people around, so it is necessary to perform a risk assessment of fusion devices. The probabilistic safety assessment (PSA) technology currently used in commercial pressurized water reactors is not applicable to fusion devices at this stage due to their structural particularity. To address this issue, this paper analyzes the differences between a fusion device and a fission device from three aspects: structural design, radioactive source term, and safety system, and proposed a preliminary probabilistic safety assessment method for fusion devices, with a case study on the ITER facility, which has been applied to a fusion experimental device under design and achieved good analytical results.Note that this method is currently validated only for ITER-like experimental devices, and its extension to other fusion plants requires further scenario-specific adjustments.In addition, the case study on ITER is based on historical design data and serves as an example application of this framework. The result does not represent the current security assessment of ITER.</p>