Abstract: Based on the finite element software UFLEX, taking 26/35 kV-3×185 mm² submarine cable as an example, the mechanical performance analysis and comparison process were elaborated in detail.The axial stiffness, torsional stiffness, bending stiffness, breaking of cables of different voltage levels and specifications, calculation results of tensile force, minimum bending radius were compared.The results showed that the stiffness of the aluminum core submarine cable was larger, but the breaking force was smaller, and the minimum bending radius was approximately equal to that of the copper core submarine cable.In terms of mechanical properties, aluminum core submarine cables need to control the allowable range of tensile force during the laying process to prevent the fracture and damage of aluminum core monofilaments.The research provided a certain scientific basis for “replacing copper with aluminum” to reduce the manufacturing cost of submarine cables.