The　dynamic　response　and　damage　mechanism　of　piers　under　underwater　explosion　loading　are　analyzed　to　investigate　the　damage　to　a　pier　caused　by　underwater　explosion　by　using　the　arbitrary　Lagrangian-Euler　method.　The　accuracy　of　the　finite　element　model　is　verified　through　an　underwater　explosion　test,　and　then　a　finite　element　model　of　a　pier　under　underwater　explosion　loading　is　established.　Taking　the　residual　vertical　bearing　capacity　of　the　pier　as　the　performance　index,　the　damage　evaluation　method　of　pier　under　explosion　loading　is　put　forward.　The　influences　of　explosive　weight　and　initiation　point　on　the　damage　degree　of　pier　are　discussed.　The　investigation　results　indicate　that　the　damage　to　the　pier　caused　by　bubble　pulsation　generated　by　a　near-field　underwater　explosion　cannot　be　ignored.　When　the　outer　side　of　pier　is　detonated,　the　TNT　weight　is　exponentially　related　to　the　residual　bearing　capacity　of　pier.　When　the　weight　of　TNT　is　the　same,　the　damage　caused　by　the　explosion　inside　the　pier　is　the　most　serious.　©　2023　China　Ordnance　Industry　Corporation.　All　rights　reserved.