Research　on　the　dynamic　discrepancy　of　the　integral　type　and　multi-section　crossrail,　jointed　by　the　high-strength　bolt　is　required.　This　paper　focuses　on　the　dynamic　characteristics　of　the　three-section　bolted　crossrail.　The　dynamic　experiment　of　the　crossrail　is　carried　out　at　three　installation　conditions,　such　as　free-free　condition,　fixed　on　machine　tool,　and　working　condition.　At　the　same　condition,　the　integral　crossrail,　which　ignore　the　bolted　joint,　is　modeled　by　three-dimensional　software　and　analyzed　by　the　finite　element　method　(FEM).　By　comparing　the　experiment　and　analysis　results,　the　influences　of　the　bolted　joints　on　three-session　beam　are　explored　and　no　signification　discrepancy　of　the　integral　and　three-section　crossrail　is　found　in　dynamic　characteristics.　Therefore,　the　bolted　joints　have　slight　influence　on　the　three-section　crossrail,　and　the　conclusion　provides　an　experimental　basis　for　the　design,　analysis　and　optimization　of　the　three-section　crossrail.