According　to　the　characteristics　of　constant　flow　and　closed　hydrostatic　rotary　table　used　in　heavy　duty　CNC　machine,　in　order　to　consider　the　interaction　between　structural　deformation　of　worktable　and　the　supporting　force　of　oil　pads,　an　iteration　method　between　hydrostatic　theory　calculation　and　finite　element　method　(FEM)　is　used　to　get　the　real　supporting　force　of　each　oil　pad　at　different　carrying　state.　The　result　is　compared　with　the　situation　which　is　not　considering　the　deformation　of　worktable　and　the　difference　between　them　can　be　used　to　guide　the　design　of　hydrostatic　oil　pads.　The　optimal　radius　of　supporting　point　of　work　piece　is　also　achieved　using　this　method,　which　can　provide　theory　basis　for　supporting　point　distribution　of　heavy　work　piece.