Aiming at the operational risk caused by melting of aircraft cable insulation layer, an aircraft cable safety analysis method based on thermal damage characteristics is proposed to accurately predict the life and dynamically assess the risk. Based on the mechanism of cable thermal damage, two types of damage characteristics including the thermal damage influence factor and the radial melting rate are defined, which characterizes the influence and degree of cable thermal damage. Use thermal damage influence factor to indicate that cable thermal damage accelerates cable failure, and a method of cable life prediction is proposed. Moreover, a dynamic risk assessment model for aircraft cable is constructed from two perspectives of thermal damage degree and failure probability. The results show that the cable life prediction method proposed owes higher accuracy and better applicability in different operating areas. The proposed risk assessment model is effective and the results are consistent with the experimental.