The　implicit　nonlinear　dynamic　analysis　of　underground　structures　is　of　poor　convergence　and　low　computational　efficiency.　Based　on　GPU　parallel　computing,　a　software　platform　for　the　explicit　dynamic　analysis　of　underground　structures　was　established,　which　can　solve　the　technical　bottleneck　of　the　implicit　method.　In　this　platform,　a　smeared　crack　model　for　concrete　was　proposed　and　implemented.　A　coupling　method　for　rebar　fibers　and　solid　elements　was　developed　and　implemented.　Based　on　the　isoparametric　element　idea,　a　method　for　calculating　the　element　area　of　artificial　boundary　nodes　was　proposed.　A　two-node　interface　element　for　solid　elements　was　proposed　to　perform　the　interaction　analysis　between　soil　and　structure　with　uncoordinated　nodes.　The　gravity　field　analysis,　linear　and　nonlinear　dynamic　analysis　of　Daikai　subway　station　in　Japan　were　performed　by　the　software.　The　results　of　gravity　field　analysis　and　linear　dynamic　analysis　were　compared　with　the　results　of　ABAQUS.　The　results　of　the　software　were　in　an　agreement　with　the　results　of　ABAQUS,　and　the　computational　efficiency　was　about　5.68　times　the　efficiency　of　ABAQUS.　Thusly,　the　accuracy　and　efficiency　of　the　software　modules　were　verified.　Besides,　the　stability　and　rationality　of　the　software　nonlinear　analysis　were　verified　by　comparing　the　results　of　nonlinear　analysis　with　the　disaster　investigation.　©　2019,　Engineering　Mechanics　Press.　All　right　reserved.