Purpose　-　This　paper　aims　to　study　the　nonlinear　supporting　performance　of　hydrostatic　ram　under　the　impact　of　cutting　force　and　search　for　an　optimal　solution　to　improve　its　stiffness.　Design/methodology/approach　-　The　Reynolds　equation　was　applied　to　resolve　the　carrying　capability　of　a　single　oil　pad　numerically,　and　an　iteration　method　was　used　to　analyze　the　nonlinear　supporting　force　and　stiffness　of　a　pair　of　oil　pads　placed　face-to-face.　The　total　offset　of　ram　could　be　obtained　after　the　displacement　of　aspectant　oil　pads　was　solved　by　the　bisection　method.　From　the　comparison　of　the　offset　values　of　ram　evaluated　under　different　support　conditions,　the　optimal　solution　was　determined.　Findings　-　In　this　study,　an　optimized　oil　supply　allocation,　concluded　as　1.16:0.84,　is　proposed　to　improve　the　performance　of　hydrostatic　ram　supporting　structure.　Originality/value　-　The　supporting　performance　of　hydrostatic　ram　could　be　improved　by　appropriate　allocation　of　oil　supply　without　extra　energy　consumption.