To explore the reason of fracture failure after Nitinol stent implantation in lower limb artery, the fatigue performance of Absolute Pro lower limb artery stent under multi-level load coupling was studied. The finite element method was used to simulate the Nitinol stent under primary (axial tensile, compression, bending, torsion, physiological pulsating cycle), secondary (tensile-bending, tensile-torsion, compression-bending, compression-torsion, bend-torsion) and third (tensile-bend-torsion, compression-bend-torsion) loads, The fatigue strength of the stent was evaluated by strain method, and the fatigue life was predicted by nominal stress method and fracture mechanics. The analysis of fatigue performance shows that the fatigue strength of the stent under the primary load and some multi-level loads can meet the requirements of 10-year fatigue life. The maximum alternate strains under the tension-bending of the second load and the tension-bending-torsion of the third load are greater than the fatigue limits, which leads to the stress concentration and fatigue failure; The life cloud diagram and safety factor show that the compressive load has the greatest influence on the stent life, and the physiological pulsating load is the smallest under the primary load; The tension-bending load has the greatest influence and the bending-torsion load has the least influence under the second load, and the tension-bending-torsion load has greater influence on the stent life than the compression-bending-torsion load under the third load. Based on fracture mechanics life prediction, it is found that the size of initial crack has a significant effect on the life of stent. The results reveal the influence of multi-level loads on the fatigue strength and life of stent, and provide theoretical reference for the clinical fracture failure mechanism of stents.