Fatigue failure of sucker rod can occur under the e ffect of alternating load, and results in failure o f sucker rod. In this paper, the damage mechanics theory is applied to the fatigue damage of sucker rod on the study, e stablish the fatigue damage evolution equation of sucker rod, an d the damage mechanics-finite element method is ado pted to solve fatigue damage of sucker rod, obtain change l aw of stress field, strain field and fatigue damage field of sucker rod, and carry out fatigue damage cycles of sucker rod. The study has a certain theoretical significan ce and practical significance on the rational use of sucke r rod, the decrease of sucker rod fracture accident and the improvement of overall economic benefits in oilfiel d development