The　direct　finite　element　method　is　a　widely　used　time　history　method　for　seismic　soil-structure　interaction　(SSI)　analysis.　In　this　method,　the　viscous-spring　boundary　condition　is　used　to　model　the　radiation　damping　of　infinite　domain,　and　the　seismic　site　response　is　transformed　into　the　equivalent　loading.　When　the　soil　layer　is　extraordinary　thick,　the　computational　efficiency　of　seismic　SSI　analysis　especially　for　three-dimensional　problem　is　very　low　due　to　the　finite　element　model　of　the　whole　deep　soil　layer.　In　this　paper,　an　efficient　analysis　scheme　is　developed.　In　which,　the　one-dimensional　site　response　analysis　is　still　performed　for　the　whole　deep　soil　layer,　and　subsequently　the　bottom　artificial　boundary　of　SSI　model　is　moved　up　from　the　actual　soil　layer　bottom　(bedrock　surface)　to　the　location　sufficiently　near　the　structure.　The　theoretical　analyses　and　numerical　examples　are　presented　to　indicate　the　accuracy　and　efficiency　of　the　proposed　efficient　analysis　scheme.　The　different　boundary　treatments　and　seismic　inputs　at　different　locations　of　the　moved　bottom　boundary　are　compared　with　the　finite　element　model　of　the　whole　deep　soil　layer.　The　proposed　scheme　meets　the　precision　requirements,　and　some　suggestions　on　artificial　boundary　treatment　and　location　are　given.　©　2019,　Engineering　Mechanics　Press.　All　right　reserved.