Electron beam welding (EBW) was applied to an 8-mm-thick new type Ti-Al-Nb-Zr-Mo titanium alloy seamless tube produced by hot continuous rolling. The microstructure and mechanical properties of welded joint were investigated. Results show that the base metal (BM) consists of primary α, transformed β and Widmanstatten structure. For the EBW joint, the fusion zone (FZ) consists of acicular α′, block α and Widmanstatten structure, and the size of acicular α′ decreases gradually from top to bottom of the FZ. Moreover, only primary α and acicular α′ form in the heat affected zone (HAZ). The average microhardness in welded joint is ranked as follows: FZ＞HAZ＞BM, and the microhardness of the HAZ decreases gradually from the FZ to the BM side. The joint's tensile strength is 893 MPa and the fracture occurs at the base metal. The elongation of tensile specimens can reach 10%. The impact energy of FZ reaches ~80% of that of BM and the bending specimens are bended to 180° without cracks.