Environmental friendly dual-fuel propelled ships are becoming popular for new shipbuilding. In order to maximize the capacity utilization and take into account the scantlings of the container hold, the type C LNG fuel tanks are transversely arranged below the superstructure in the large dual-fuel container ships. Compared with the LNG carrier, the safety of the traditional saddle structure becomes insufficient due to the significant changes of the load acted on the hull. The optimized arrangement plan and structure design of the saddle are proposed in the current study. The strength and fatigue of the saddle and its supporting structure are analyzed by using the finite element method, and compared with those of traditional saddle design. The results show that the optimized saddle structure can significantly improve the stress distribution and increase the fatigue life. It can provide references for the structure design of the saddle for large container ships with type C LNG fuel tanks.