In this work, the research progress on diffusion bonding of titanium alloys and fatigue crack growth (FCG) behavior of their laminates are briefly reviewed. Furthermore, the microstructural evolution and FCG characteristics at the interfaces of titanium alloys subjected to diffusion bonding are summarized. Firstly, the application background and advantages of superplastic forming/diffusion bonding technology are outlined, as well as some auxiliary technologies to improve the diffusion bonding interface quality of titanium alloys, such as the interlayer addition, thermohydrogen treatment, pulse current heating, and surface modification. The microstructures and mechanical properties of the bonded interfaces are shown based on the diffusion bonding of titanium alloys and titanium alloys with other alloys. The strong dependence of microstructural evolution on the alloy elements and interdiffusion ability of elements at the bonded interfaces is clarified. Diffusion bonding process can be used to fabricate the laminates of the same and different alloys, and the shape and distribution of the bonded and unbonded zones at the interfaces can be flexibly controlled. Finally, the diffusion bonding laminates with the same or different titanium alloys can be used to reduce the FCG rate. Therefore, the fatigue damage tolerance of titanium alloy components is optimized.