Taking　a　certain　twin-tube　shield　tunnel　of　Beijing　metro　closely　under-crossing　the　existing　rectangular　mined　tunnel　as　an　example,　the　3D　numerical　model　for　double-decked　intersecting　metro　tunnel　with　different　cross　angles　was　established.　Kobe　wave　and　Beijing　artificial　wave　was　taken　as　the　input　seismic　wave　of　bedrock.　The　seismic　response　characteristics　under　strong　horizontal　ground　motion　were　studied　and　the　results　were　compared　with　those　of　single-layer　rectangular/circular　tunnels.　The　results　showed　that　the　interaction　effect　of　double-decked　closely-intersecting　tunnels　amplified　the　peak　values　of　the　relative　horizontal　displacement　and　vibration　acceleration　of　the　top　layer　and　bottom　layer　tunnels,　and　it　decreased　with　the　increase　of　cross　angle.　The　seismic　stress　of　the　rectangular　tunnel　on　the　top　layer　was　increased　while　that　of　the　circular　tunnel　on　the　bottom　layer　was　reduced.　The　interaction　effect　of　intersecting　metro　tunnels　was　closely　related　to　the　cross　form　and　the　characteristics　of　the　input　seismic　wave　of　bedrock.　The　weak　parts　of　the　tunnel　structure　were　the　roof　of　rectangular　tunnel　on　the　top　layer,　the　connection　part　of　floor　and　side　wall,　the　top　and　bottom　of　the　pillar　(central　column)　as　well　as　the　spandrel　and　the　hance　of　the　circular　tunnel　on　the　bottom　layer.　The　seismic　deformation　patterns　of　rectangular　tunnel　and　circular　tunnel　were　respectively　similar　to　the　monotone　increasing　of　sine　curve　and　reversed　S-shaped　curve.　The　site　soil　deformation　was　mainly　shear　deformation.　The　contact　surface　between　soil　and　structure　was　weak　when　the　earthquake　would　happen.　©,　2015,　Chinese　Academy　of　Railway　Sciences.　All　right　reserved.