As　one　of　the　most　important　mechanical　parameters　of　magnetorheological　fluids　(MRF),　the　normal　force　has　been　studied　by　a　large　number　of　researchers　using　various　experimental　equipment　and　methods.　However,　it　is　difficult　to　reveal　the　effects　of　particle　microstructure　characteristics　on　the　normal　force　of　MRF　by　experimental　methods,　especially　for　such　factor　as　the　particle　size　distribution.　To　advance　this　research　area,　a　numerical　method　for　calculating　the　normal　force　of　MRF　is　proposed　in　this　study.　The　accuracy　of　the　simulation　model　is　verified　with　the　experimental　results　measured　by　a　plate-plate　magnetorheometer.　The　results　show　that　the　simulated　values　agree　well　with　the　experimental　data,　which　indicates　the　feasibility　of　calculating　the　normal　force　of　MRF　using　numerical　methods　and　provides　a　new　research　idea　for　a　more　intuitive　and　comprehensive　analysis　of　the　normal　force　characteristics　of　MRF.　Besides,　the　simulated　data　show　that　the　increase　in　magnetic　field　intensity　and　particle　volume　fraction　will　sufficiently　enhance　the　normal　force　of　MRF　and　improve　the　response　time　of　MRF.　For　the　MRF　with　the　same　particle　volume　fraction,　a　decline　in　the　average　particle　diameter　will　increase　the　normal　force.　Moreover,　increasing　the　dispersion　of　particle　size　of　MRF　particles　can　also　improve　its　normal　force.　©　2023　The　Author(s).　Published　by　IOP　Publishing　Ltd.