During the annual inspection of a dynamic submarine cable, it is found that the cable protection jacket above the cable lock clip falls off and the armor is exposed, which affects the safety production. The analysis model is established with the OrcaFlex software. Combined with the different operating conditions of Floating Production Storage and Offloading (FPSO), the structural strength analysis and fatigue analysis are made for the structural state of submarine cable. It is calculated that the offset of FPSO under typhoon condition is an important factor affecting the structural strength of submarine cable. The structural strength and fatigue life meet the requirements due to the low load at the damaged location of protective jacket of submarine cable. The corrosion rate of armored layer is calculated according to the relevant literature, and the strength of submarine cable meets the requirements.