Offshore　bridges　can　be　affected　by　disasters,　such　as,　tsunami　wave　or　storm　surge　in　extreme　climate.　Here,　flume　model　tests　were　conducted　to　study　wave　force　action　law　of　tsunami　wave　on　offshore　bridge　structures.　The　test　prototype　was　A-ramp　bridge　of　Yanwu　Bridge　in　Xiamen　City,　its　upper　part　was　a　streamlined　3-chamber　box　girder　and　its　lower　part　was　a　cylindrical　pier.　Its　model　with　scale　of　1　25　was　used　to　conduct　tsunami　wave　impact　tests,　and　study　characteristics　of　wave　force　exerted　on　box　girder　and　pier　structure　under　different　tsunami　wave　conditions.　The　results　showed　that　when　wave　just　strikes　main　girder,　due　to　action　of　hydrodynamic　impact　force,　pressure　exerted　on　the　structure　can　reach　the　maximum　peak　immediately;　then　when　wave　current　gradually　submerges　bridge　body,　its　pressure　tends　to　change　stably　due　to　action　of　hydrodynamic　pressure;　under　different　wave　velocities　or　impact　submergence　coefficients,　peak　value　of　vertical　force　exerted　on　the　structure　is　always　about　twice　that　of　horizontal　force;　variation　of　wave　velocity　or　impact　submergence　coefficient　has　more　obvious　impact　on　horizontal　force　exerted　on　the　structure;　when　wave　height　is　unchanged,　with　increase　in　wave　velocity,　peak　pressure　exerted　on　pier　increases　significantly;　when　wave　velocity　is　unchanged,　variation　of　wave　height　has　smaller　impact　on　peak　pressure　exerted　on　pier,　so　wave　force　exerted　on　pier　is　more　sensitive　to　variation　of　wave　velocity.　©　2022　Chinese　Vibration　Engineering　Society.　All　rights　reserved.