The fretting fatigue contact problem of dovetail joints between blade and disk in aero-engine was simplified due to geometric characteristic of the contact area. The stress

strain and displacement between these two contact bodies were obtained through the finite element method for numerical simulation of the simplified model. A fretting damage parameter was introduced and the research on the fretting fatigue life prediction model was carried out

based on the critical plane theory and fretting damage mechanism. The results confirm the validity of the life prediction model by comparing the estimated fretting fatigue life with the experimental life of TC11 and dovetail joints. And the errors are within 2 times of dispersion band.