Fatigue failure of riveted buttsingle strap joints frequently occurs around the fastener hole. In order to improve the fatigue life of the rivet joints, fatigue life improving techniques such as interference fit methods are used. This dissertation focuses on the study of predicting the fatigue life of buttsingle strap joints with interference fit based on continuum damage mechanics. Damage mechanicsfinite element method(DMFE) of structure fatigue crack initiation life prediction under cyclic loading is presented with ANSYS Secondary Development by APDL to compute the fatigue life of interference fit riveted buttsingle strap joints. Comparison between the results of SWT and DMFE shows the accuracy of DMFE is acceptable.