Redundantly　actuated　parallel　manipulator　(RAPM)　has　been　proved　to　have　comparative　advantages　of　higher　rigidity　and　higher　payload　over　other　parallel　manipulators.　This　paper　is　to　establish　a　sufficient　accurate　stiffness　modelling　to　evaluate　the　stiffness　of　the　2UPR-2RPS　RAPM.　Firstly,　the　structure　of　the　2UPR-2RPS　RAPM　is　briefly　introduced,　followed　by　some　necessary　kinematic　definitions.　Next,　a　stiffness　modelling　of　2UPR-2RPS　is　established　by　including　the　compliances　of　all　joints　and　limb　structures.　And　a　reasonable　index　is　constructed　to　evaluate　the　stiffness　of　the　2UPR-2RPS　RAPM.　Finally,　a　set　of　stiffness　experiments　is　carried　out　to　verify　the　effectiveness　of　the　proposed　stiffness　modelling　of　the　2UPR-2RPS.　The　results　indicate　that　the　relative　errors　between　the　proposed　stiffness　modelling　and　the　experimental　value　are　less　than　6%.　This　indicates　that　the　proposed　stiffness　modelling　possesses　sufficient　accuracy　and　thus　can　be　used　to　analyze　the　stiffness　of　the　2UPR-SRPS　RAPM.　©　The　Author(s),　under　exclusive　license　to　Springer　Nature　Singapore　Pte　Ltd.　2025.