The Ti-24Al-15Nb-1.5Mo/TC11 dual alloy discs were joined by electron beam welding firstly, and then underwent near isothermal forging and gradient heat treatment. The welding interface state was investigated by OM, SEM, TEM and XRD. The results show that the elevated temperature properties of the dual alloy disc are better and the high temperature strength is larger than that of the TC11 alloy. However, the dispersion degree of tensile properties is larger at the room temperature. When the dual alloy disc is deformed by 50%, the α phase is distributed in the β phase grain boundary from welding seam to the heat-affected zone of TC11 alloy, which can not be eliminated by gradient heat treatment. The cluster α2 phase in the welding seam area is formed, which is ascribed to the diffusion of the Al and Nb elements from the α2 phase during near isothermal forging and gradient heat treatment.