In　order　to　study　the　dynamic　response　characteristics　of　the　immersed　tunnel　under　the　horizontal　ground　motion,　a　3-D　finite　element　model,　considering　the　seawater-seabed-segment　interaction,　was　established　using　the　ABAQUS　software　platform,　with　the　Hong　Kong-Zhuhai-Macao　Bridge　Immersed　Tube　Tunnel　as　the　research　context.　The　model　also　incorporated　the　nonlinear　dynamic　characteristics　of　seabed　soil　and　the　plastic　damage　behavior　of　the　tunnel　concrete.　The　seismic　response　of　the　tunnel　segments　to　varying　levels　of　ground　motions　was　analyzed　using　the　dynamic　time　history　analysis.　The　results　indicate　that　the　initial　damage　occurs　at　the　connection　between　the　middle　wall　and　the　roof　of　the　tunnel,　but　the　folded　arch　section　experiences　the　most　severe　post-earthquake　damage,　making　it　the　weakest　part　of　the　tunnel.　When　the　peak　ground　acceleration　of　input　ground　motion　exceeds　0.　4g,regions　such　as　the　folded　arches　and　the　side　walls　will　become　susceptible　to　post-earthquake　water　seepage　secondary　hazards.　The　above　research　results　can　serve　as　a　valuable　reference　for　the　seismic　performance　design　of　immersed　tunnels.　©　2023　Science　Press.　All　rights　reserved.