Vibration　energy　harvesting　has　attracted　considerable　attention　because　of　its　application　prospects　for　charging　or　powering　micro-electro-mechanical　system.　Abundant　hydrokinetic　energy　of　water　at　low　velocity　is　contained　in　the　fluid　environment,　such　as　rivers　and　oceans,　which　are　widely　existing　in　nature.　In　this　paper,　a　flow-induced　piezoelectric　vibration　energy　harvester　(PVEH)　with　magnetic　force　enhancement,　which　is　integrated　by　piezoelectric　beam,　circular　cylinder　bluff　body　and　magnets,　is　proposed　and　experimental　investigated.　It　could　transfer　the　hydrokinetic　energy,　both　the　vortex-induced　vibration　and　magnetic　force　excitation　underwater,　into　electricity.　First,　the　frequency　sweep　experiment　of　the　piezoelectric　cantilever　beam　is　carried　out　to　determine　the　resonance　frequency　where　the　effect　of　magnetic　force　on　the　vibration　characteristic　is　obtained.　Furthermore,　the　flow-induced　vibration　experiment　platform　is　setup　and　the　energy　harvesting　performance　of　the　PVEH　is　investigated　in　detail.　The　effects　of　the　magnet　property,　flow　velocity　and　the　magnetic　poles　distance　on　the　vibration　frequency　and　the　acquisition　voltage　are　demonstrated　and　discussed.　The　results　show　that　it　could　improve　the　harvesting　performance　by　introducing　magnetic　force.　It　has　advantages　in　higher　output　voltage　for　the　flow-induced　PVEH,　especially　in　low　velocity　water　flow,　when　the　flow　velocity　is　0.35　m/s,　the　PVEH　under　attractive　magnetic　force　with　magnetic　distance　of　20　mm　scavenges　the　higher　acquisition　voltage　of　5.2　V,　which　is　increased　by　225%　than　the　PVEH　with　non-magnetic.　The　results　can　be　applied　to　guide　further　fabrication　process　and　optimized　design　of　the　proposed　flow-induced　PVEH　underwater　with　low　flow　velocity.