To address the issue of creep in the bending restrictors of submarine cable, tensile creep tests are designed and carried out on polyurethane material, and a creep constitutive model for polyurethane based on time-hardening model is obtained. Based on the creep characteristics of the polyurethane material, a numerical analysis method considering creep for the bending restrictor structure is established using Abaqus software. The strength and bending protection performance analysis is carried out on a typical bending restrictor as an example. The changes in strain, stress and overall curvature radius over time of the bending restrictor are obtained under a constant bending moment applied for up to one year. The results show that the long-term load is of a more significant effect on the curvature radius than on the peak strain and stress, that is, the loss of bending protection performance is more likely to occur than the strength failure when used for a long time.