Dynamic　soil-structure　interaction　is　a　wave　propagation　problem　on　unbounded　domain.　An　explicit　finite　element　artificial　boundary　scheme　that　couples　the　standard　dynamic　finite　element　method　and　a　high-order　accurate　artificial　boundary　condition　(ABC)　is　proposed　to　solve　the　unbounded　wave　problem.　The　out-of-plane　wave　equation　is　considered　in　this　paper.　An　exact　dynamic-stiffness　ABC　that　is　global　in　space　and　time　is　constructed.　A　temporal　localization　method　that　consists　of　the　rational　function　approximation　and　the　auxiliary　variable　realization　is　developed.　This　method　is　applied　to　the　dynamic-stiffness　ABC　to　result　in　a　high-order　accurate　ABC　that　is　local　in　time　but　global　in　space.　By　discretizing　the　high-order　accurate　ABC　along　artificial　boundary　and　coupling　the　result　with　the　standard　lumped-mass　finite　element　equation　of　near　field,　a　coupled　dynamic　equation　is　obtained,　which　is　a　symmetric　system　of　purely　second-order　ordinary　differential　equations　in　time　with　the　diagonal　mass　and　non-diagonal　damping　matrices.　A　new　explicit　time　integration　algorithm　in　structural　dynamics　is　used　to　solve　this　equation.　Numerical　examples　demonstrate　the　effectiveness　of　the　proposed　explicit　finite　element　artificial　boundary　scheme.