The bending free span could be formed on in-service XLPE submarine power cable due to current scouring, the unevenness of seabed or other factors, which may result in the excessive deformation or damage of the cable structure. Bending stiffness is the key parameter to analyze the bending response of XLPE submarine power cable. With consideration of the non-linear behavior of slip contact between components, a three-dimensional finite element model is established for the XLPE submarine power cable by ABAQUS, with which the bending stiffness of the cross-section is calculated. The pure bending test of XLPE submarine power cable is carried out, the finite element model is verified by the comparison of test result of bending stiffness and the one of numerical simulation calculation. Based on this model, the sensitivity of tension, helical angle and friction coefficient to the bending stiffness of XLPE submarine power cable is studied. The study results can provide a strong technical support for the design and analysis of the XLPE submarine power cable and its application. Simulation results on actual wind farm data validate the effectiveness of the proposed method.