The　polishing　mechanism　of　bonnet　polishing　(BP)　and　the　tool　influence　function　(TIF)　of　bonnet　tool　have　been　widely　studied.　However,　most　of　current　studies　pay　little　attention　to　the　influence　of　polishing　slurry　on　the　BP　mechanism　as　well　as　TIF.　This　study　proposes　that　the　interfacial　contact　state　between　the　polishing　tool　and　the　workpiece　is　in　a　mixed　lubrication　state,　subsequently　the　BP　mechanism　is　further　explored.　It　is　found　that　the　workpiece　material　is　removed　by　polishing　pad　and　abrasives.　The　polishing　slurry　is　not　directly　involved　in　workpiece　removal,　but　shares　the　normal　pressure　of　the　polishing　tool　on　workpiece,　which　affects　material　removal.　Based　on　the　above　mechanism,　the　TIF　removal　prediction　model　is　established　and　verified　by　experiments.　The　results　show　that　the　maximum　error　of　the　model　prediction　value　is　quiet　small,　which　verifies　the　model.　Moreover,　compared　with　Preston　model　and　the　previous　model,　which　ignored　the　influence　of　the　fluid,　the　average　prediction　error　of　the　model　in　this　paper　when　D-0　=　20　mm　is　6.38　%,　while　the　previous　model　and　Preston　model　are　11.21　%　and　49.10　%,　respectively.　Which　illustrates　the　model　in　this　paper　has　higher　accuracy.