Thick-walled　structures,　such　as　marine　engineering　and　rail　transportation,　are　widely　used　in　modern　society.　V-groove　welding　is　a　common　welding　method　in　thick　structures.　At　the　same　time,　the　V-groove　weld　is　also　the　area　of　a　thick-walled　structure　in　which　defects　are　most　easily　formed.　Laser-generated　surface　acoustic　waves　are　a　promising　non-destructive　testing　method　in　most　fields.　This　study　examined　the　propagation　characteristics　of　laser-generated　surface　acoustic　waves　in　a　V-groove　weld.　A　two-dimensional　finite　element　model　with　Q345　steel　was　constructed.　A　thermoelastic　mechanism　was　adopted　to　generate　the　wave.　The　temperature　and　displacement　fields　were　analyzed　in　detail.　The　results　showed　that　wave　transmission,　reflection,　and　mode　conversion　are　generated　with　an　R　wave　at　the　junction,　and　the　dispersion　phenomenon　of　the　R　wave　occurred　in　the　welded　area.　　©　Published　under　licence　by　IOP　Publishing　Ltd.