Interaction　between　underwater　shock　waves　and　structures　has　attracted　significant　interest　of　many　researchers.　This　study　aims　to　develop　a　method　to　solve　two-dimensional　(2　D)　fluid-structure　interaction　problems　during　far-field　underwater　explosion　(UNDEX).　The　acoustic　domain　which　can　undergo　small　pressure　variations　is　considered　to　describe　the　fluid-structure　interaction　during　UNDEX.　First,　the　empirical　formula　of　the　incident　shock　waves　is　considered　as　free　wave　motion　of　the　fluid,　and　the　fluid　domain　is　Discretized　by　the　finite　element　method.　Based　on　the　scaled　boundary　finite　element　method　(SBFEM)　and　continued　fraction　solution,　an　artificial　boundary　condition　(ABC)　with　high　accuracy　in　time　domain　is　adopted　to　simulate　the　truncated　infinite　domain,　which　can　be　placed　very　close　to　the　radiating　field　is　adopted　to　simulate　the　truncated　infinite　domain.　Third,　an　internal　substructure　method　(ISM)　to　calculate　the　equivalent　input　shock　wave　loads　is　proposed.　Finally,　the　proposed　method　is　used　to　study　the　scattered　waves　on　a　rigid　circular　structure　due　to　the　shock　wave,　and　the　effect　of　the　radiation　wave　due　to　the　motion　of　the　structure　on　the　dynamic　responses　of　the　circular　structure　during　UNDEX　is　studied.