Objective　Venous-arterial　venous　extracorporeal　membrane　oxygenation　(V-AV　ECMO),　as　a　new　clinical　application　of　ECMO,　showed　great　clinical　application　potential　in　the　treatment　of　patients　with　combined　cardiopulmonary　failure.　Given　the　complicated　cannulation　strategy　of　V-AV　ECMO,　its　influence　on　the　hemodynamics　of　the　human　circulatory　system　remained　unclear.　Methods　In　this　paper,　a　fluid-structure　interaction　was　used　to　study　the　effect　of　V-AV　ECMO　oxygenated　blood　shunt　ratio　on　right　atrial　recirculation　and　tricuspid　valve　(TV)　blood　oxygen　saturation.　In　this　study,　the　right　atrium,　superior　vena　cava　supplying　cannulae　and　inferior　vena　cava　draining　cannulae　model　of　a　specific　patient　was　constructed.　Seven　cases　with　shunt　ratio　of　12.50%,　18.75%,　25.00%,　31.25%,　37.50%,　43.75%　and　50.00%　were　designed.　Results　The　streamline　diagram　and　velocity　contour　of　oxygenated　blood,　recirculation　fraction　(RF),　correlation　of　three　variables　(shunt　ratio,　RF,　and　oxygen　saturation),　and　the　oxygen　saturation　of　blood　at　the　TV　were　extracted　for　the　study.　Study　results　showed　that,　first,　as　the　shunt　ratio　increased,　the　RF　of　the　seven　cases　was　14.64%,　29.87%,　33.85%,　40.12%,　40.40%,　40.02%,　and　38.09%.　Second,　with　the　increase　of　the　shunt　ratio,　oxygen　saturation　of　blood　at　the　TV　in　seven　cases　was　82.1%,　82.5%,　83.3%,　83.3%,　84.0%,　84.6%,　and　85.3%.　Conclusions　In　this　study,　the　shunt　ratio　had　a　strong　correlation　with　the　RF　and　oxygen　saturation　of　blood　at　the　TV.　As　the　shunt　ratio　increased,　the　RF　initially　increased　and　then　stabilized.　However,　oxygen　saturation　of　blood　at　the　TV　would　increase　with　the　increase　of　the　shunt　ratio,　but　the　degree　of　increase　was　small.　This　research　provided　useful　information　for　surgeons　and　operators　using　V-AV　ECMO.