Load　eccentricity　and　contact　stress　of　load　pads　with　different　contact　forms　were　compared.　9　pieces　of　load　pads　with　different　structures　were　designed　and　tested.The　experimental　results　show　that　the　position　errors　of　the　sphere-plane　contact　are　smaller　than　that　of　sphere-sphere　point　contact.Load　eccentricities　with　sphere-sphere　uniform　contact　and　sphere-plane　contact　are　similar.　The　sphere-sphere　point　contact　and　the　sphere-sphere　uniform　contact　are　suitable　for　the　situations　when　the　angle　of　adjustment　is　small.The　sphere-plane　contact　and　the　sphere-sphere　uniform　contact　with　small　radius　are　used　if　the　angle　of　adjustment　is　large.　©　2019,　China　Mechanical　Engineering　Magazine　Office.　All　right　reserved.