[Objective]　The　study　investigates　the　impact　process　of　plunging　waves　on　the　pile-plate　bridge　structure　in　three　stages　of　to　be　crushed,　being　crushed　and　completed　crushing.　It　reveals　the　influences　of　beam　plate　and　pier　on　each　other’s　mutual　force;　and　explore　the　influencing　rule　of　pier　diameter　and　pier　height　on　beam　plate　and　pier　stresses.　[Method]　Relying　on　the　new　type　pile-plate　bridge　engineering　in　the　coastal　section　of　Binhai　national　highway　in　Fujian　Province,　with　the　CFD　software　Flow-3D,　a　three-dimensional　numerical　model　of　integral　wave　flume　with　structural　section　was　established.　The　model　accuracy　was　verified　by　comparing　with　the　physical　model　test.　The　wave　force　differences　of　beam-plate　system　with　pier,　independent　beam-plate　without　pier　and　independent　pier　without　beam-plate　were　compared　and　analyzed.　The　influencing　rule　of　pier　diameter　and　pier　height　on　beam-plate　and　pier　stresses　was　systematically　investigated.　[Result]　When　plunging　waves　impact,　the　blocking　effect　of　plate　and　pier　aggravates　the　movement　of　water　particles　at　the　joint.　The　impact　at　the　joint　between　plate　and　pier　is　significant.　The　plate　and　pier　have　strong　amplification　effect　on　each　other’　s　mutual　force.　The　vertical　wave　force　on　plate　can　be　amplified　6.　07　times　by　plunging　waves　in　completed　crushing　stage.　The　horizontal　wave　force　on　pier　from　far　shore　side　to　near　shore　side　can　be　amplified　1.　86　times,　1.　35　times　and　1.　42　times　by　plunging　waves　in　the　to　be　crushed　stage.　[　Conclusion]　With　the　increase　of　pier　diameter,　the　amplifying　effect　of　plate　and　pier　on　each　other’　s　mutual　force　is　enhanced.　It　leads　to　the　increase　of　vertical　wave　force　on　plate　and　horizontal　wave　force　on　pier,　especially　in　the　stage　of　to　be　crushed.　The　increase　of　pier　height　causes　the　decrease　of　plate　horizontal　and　vertical　wave　force.　The　influence　on　horizontal　wave　force　is　the　most　significant　in　the　stage　of　to　be　crushed.　The　influence　on　vertical　wave　force　is　the　most　significant　in　the　stage　of　completed　crushing.　In　addition,　the　pier　height　variation　will　also　cause　the　horizontal　wave　force　of　pier　varying　in　different　rules.　©The　Author(s)　2025.