Cavitation　erosion　test　of　copper-bearing　antibacterial　duplex　stainless　steel　in　artificial　seawater　was　carried　out　by　using　a　magnetostrictive　cavitation　test　machine,　and　the　cumulative　loss　weight　and　weight　loss　curve　were　measured　by　weight　loss.　The　cavitation　erosion　mechanism　was　analyzed　by　OM,　ESEM,　EDS,　XRD　and　so　on.　The　results　reveal　that　the　cavitation　erosion　of　the　copper-bearing　antibacterial　duplex　stainless　steel　after　aging　treatment　at　560℃　is　divided　into　initial　period,　accelerated　period,　decreased　period　and　stable　period.　Compare　with　the　base　material,　the　cavitation　damage　of　copper-bearing　antibacterial　duplex　stainless　presents　more　serious.　After　50h,　the　weight　loss　of　corrosion　resistance　of　antibacterial　materials　and　solution　material　reach　2.5mg　and　4.2mg,　respectively,　and　the　cavitation　damage　of　copper-bearing　antibacterial　duplex　stainless　steel　after　antibacterial　aging　is　reduced.　The　fine　and　dispersion　Cu-rich　phase　in　antibacterial　material　can　enhance　the　cavitation　erosion　resistance　of　ferrite,　however　the　crystal　structure　of　austenite　and　the　sliding　hindrance　caused　by　internal　dislocation　determine　that　the　cavitation　erosion　resistance　is　the　higher　than　the　ferrite　with　Curich　phase.　The　micro-hardness　of　the　antibacterial　material　and　solution　material　is　increased　with　the　increase　of　cavitation　time,　however,　the　hardness　value　of　antibacterial　material　is　always　higher　than　that　of　solid　solution　ones　due　to　the　dispersion　of　aging　precipitation　and　rich　Cu　phase.　©　2018,　Journal　Office　of　Special　Casting　and　Nonferrous　Alloys.　All　right　reserved.