When　a　multi-component　force　sensor　calibrated　in　the　build-up　type　multi-component　force　calibration　machine,　its　deformation　caused　by　the　load　applied　in　one　direction　would　induce　the　deflections　in　the　series　connection　components　in　other　directions,　in　which　case　the　lateral　forces　would　generate　and　applied　to　the　reference　sensor　of　the　machine　leading　to　deviations　in　the　sensor　readings.　To　address　the　above　problems,　this　study　adopted　a　two-axis　rectangular　flexure　hinge　as　a　series　connection　component　and　investigated　how　its　geometric　parameters　influence　the　coupling　effects　in　force　sensors　(reference　sensors).　The　findings　reveal　a　clear　relationship　between　the　hinge　of　each　parameter　and　the　coupling　effects,　providing　valuable　insights　for　optimizing　the　design　of　multi-component　force　sensor　calibration　machines　and　reducing　inter-component　coupling.　Firstly,　a　mechanical　model　of　the　flexure　hinges　is　derived　based　on　material　mechanics.　Finite　element　method　(FEM)　simulations　are　then　employed　to　investigate　the　influence　of　geometric　sizes-width　(b),　thickness　(h),　and　length　(l)-on　the　reaction　forces　at　the　fixed　end.　Subsequently,　15　flexure　hinges　with　varying　geometric　sizes　are　designed　and　mounted　on　the　force　sensor　to　conduct　coupling　experiments.　The　variations　in　the　coupling　rate　are　quantitatively　analyzed,　and　the　accuracy　of　the　FEM　results　is　verified.　The　results　show　that　the　greater　the　deflection　applied　at　the　loading　end　of　the　two-axis　rectangular　flexure　hinges　is,　the　larger　the　reaction　force　at　the　fixed　end　will　be,　thereby　intensifying　the　coupling　effect　on　the　force　sensor　output.　Flexure　hinges　with　more　minor　b　and　h,　as　well　as　longer　l,　reduce　the　coupling　effects　introduced　by　the　deflection　at　the　loading　end.　Among　the　above　elements,　reducing　h　is　the　most　effective　approach　of　minimizing　coupling.　Furthermore,　two-axis　rectangular　flexure　hinges　exhibit　directional　compliance　around　the　radial　direction,　which　results　in　different　coupling　rates　in　the　y　and　z　directions　when　deflections　are　the　same.