Currently,　the　shear　pin　connection　(SPC)　is　a　structural　measure　in　the　double　spherical　seismic　isolation　bearing　(DSSIB).　However,　there　is　no　unified　design　methodology　for　the　SPC.　In　addition,　the　existing　shear　constitutive　model　is　the　linear　elastic　model　(LEM).　Its　drawback　is　the　inability　to　capture　the　gap　in　the　bearing　and　the　plasticity,　damage,　as　well　as　fracture　behavior　of　the　SPC.　Therefore,　based　on　the　performance　requirements　for　two-level　seismic　fortification,　a　detailed　design　methodology　for　the　SPC　is　proposed.　With　the　SPC　in　the　Fuzhou　Daoqingzhou　Bridge　as　a　prototype,　the　finite　element　model　of　the　SPC　is　developed　in　order　to　discuss　the　applicability　of　the　LEM　for　predicating　the　shear　behavior　of　SPC.　The　results　showed　that　the　fracture　displacement　and　absorbed　energy　obtained　by　the　finite　element　analysis　were　significantly　larger　than　those　predicted　by　the　LEM.　Then,　to　compensate　the　drawback　of　the　LEM,　a　tri-linear　model　(TLM)　is　proposed　as　the　modified　shear　constitutive　model　of　the　SPC.　Finally,　the　effects　of　TLM　and　LEM　of　the　SPC　on　seismic　performance　of　the　isolated　bridge　were　investigated.　Obviously,　the　maximum　displacement　of　the　bearing　calculated　by　the　TLM　is　up　to　1.38　times　that　calculated　by　the　LEM.　This　suggests　that　the　TLM　has　accurate　predictions　of　mechanical　property　of　the　SPC.