Abstract: Five kinds of commonly used marine cables are selected, and the influence of radiation intensity, cable size and structure on the heat release rate of cable are analyzed by cone calorimeter. The fire escape index is calculated by the peak time of cable ignition and the peak of heat release rate to characterize the fire hazard. The results show that the high radiation intensity will reduce the ignition time and improve the peak heat release rate, but does not change the cable burning process. Cable with large size has a long ignition time, high heat release rate and high fire hazard. The sheath material has a great impact on the fire spread. Under the premise of ensuring the electrical and mechanical properties of the cable,the thin sheath can reduce the fire spread rate. The application of the wire braid in the cable can significantly reduce the cable fire hazard.