Fretting　usually　occurs　between　contact　surfaces,　and　the　amplitude　of　mutual　motion　of　contact　surfaces　is　at　the　micron　level.　In　this　paper,　the　sphere-on-plate　contact　model　of　the　contact　surface　between　cortical　bone　and　Ti-6Al-4V　was　established.　Based　on　Archard　wear　equation,　the　fretting　wear　behavior　was　simulated　by　UMESHMOTION　subroutine　in　ABAQUS　software.　The　effects　of　fretting　displacement　amplitude　on　the　surface　wear　process　of　Ti-6Al-4V　was　studied.　It　was　found　that　the　fretting　slip　state　changed　from　partial　slip　state　to　gross　slip　state　with　the　increase　of　displacement　Amplitude,　and　the　wear　depth　increased　significantly　at　the　same　time.　This　study　provided　a　theoretical　basis　for　the　study　of　fretting　wear　between　titanium　alloy　medical　devices　and　cortical　bone.　©　2021　IEEE.