Based on the analysis of the current situation of lightning disaster risk assessment, the demands for delicacy assessment are analyzed. Taking a bridge tower’s elevator assessment as an example, the methods of lightning disaster risk assessment of specific objects are studied. Based on the systemic analysis of lightning damage approaches, the fault tree analysis (FTA) method is introduced and used to establish models, analyze and assess the causal relation of elevator lightning damage events, so to calculate the annual probabilities of elevator lightning damage events and the most effective factors influencing the lightning damage probability and the most critical and optimal control of elevator lightning damage events.