Magnetorheological　fluid　seal　and　brush　seal　are　successful　sealing　forms.　To　address　problems　such　as　pole　pieces　colliding　with　spindles,　precise　sealing　clearance　in　magnetic　fluid　seals,　and　inevitable　leakage　in　brush　seals,　this　article　combines　the　advantages　of　magnetic　fluid　seal　and　brush　seal　and　proposes　a　magnetorheological　fluid　seal　with　flexible　pole　pieces.　The　magnetic　field　of　the　seal　was　estimated　using　the　finite-element　method　and　the　seal　capacity　was　studied　in　theory.　Single　structural　parameters　of　the　seal　that　affect　sealing　capacity　such　as　the　relative　permeability　and　thickness　were　discussed.　The　combined　effects　of　various　structural　parameters　were　analyzed.　The　results　show　that　an　increase　in　the　relative　permeability　and　length　of　the　flexible　pole　pieces　leads　to　the　enhancement　of　the　seal　capacity.　The　thickness　of　the　flexible　magnetic　pole　piece　and　the　magnetic　part　of　the　flap　and　coating　are　inversely　proportional　to　the　sealing　pressure　value.　The　experimentally　obtained　seal　capacity　agrees　with　the　value　calculated　through　the　simulation.　This　article　presents　a　structure　of　the　magnetorheological　fluid　seal　and　comparative　results　of　the　seal　capacity　obtained　from　both　experimental　studies　and　numerical　simulation　calculations.