The microstructures and mechanical properties of laser welded Ti-22Al-27Nb alloy sheet joints are investigated under hot rolling, heat treatment of 1080 ℃/40 min/water-cooling (HT1), and heat treatment of 980 ℃/3 h/oil-cooling (HT2). The well-formed welds are obtained with the process parameters of laser power of 1500 W and welding speed of 1 m/min. The microstructures of hot rolled, HT1 and HT2 sheet joints are B2+O+α2 phase, B2 phase, and B2+O+α2 phase, respectively. From the fusion line to the base metal, the microstructures of heat affected zones for hot rolled and HT2 sheet joints are the B2, B2+α2, and B2+O+α2 phase zones, respectively, however, those of HT1 sheet joints are only single B2 phase. The tensile strengths of hot rolled sheet joints at room temperature and 650 ℃ are 1023 MPa and 675 MPa, and the elongations are 5.48% and 2.56%, respectively. In contrast, the tensile strength of HT2 sheet joints are 860 MPa and 680 MPa, and the elongations are 7.04% and 4.97%, respectively.