Abstract: The welding of Ti700sr high-temperature titanium alloy plate was conducted with TIG technology, and the microstructure, hardness distribution and tensile properties of the welded joints were analyzed. It was confirmed that the joint was well formed after welding. The weld zone was composed of coarse columnar crystal and slender acicular α phase, the heated affected zone was composed of slender acicular α phase and residual β phase. The precipitation in HAZ was effectively controlled, and there was no obvious silicide precipitation on the phase boundary. In general, the hardness of HAZ was relatively higher and the hardness of weld low. The strength of the joint was about 903 MPa at room temperature and 397 MPa at 700 ℃. The strength of the weld was lower than that of the base metal.