Abstract: Through the heat treatment experiment of Ti-6A1-4V titanium alloy bolt fasteners, the effects of solution and solution aging heat treatments on the microstructure distribution of Ti-6A1-4V fasteners were compared and analyzed, and the microhardness distribution of the bolt fastener was obtained by the microhardness meter.The results show that the number and size of primary α structure decreases after the Ti-6A1-4V bolt is solid-solution treated, while the number of needle-like α structure increases, and the primary α structure is dissolved. After the bolts are treated with solution and aging, the equiaxed primary α-phase structure becomes a lamellar structure of large-grain β-phase, and the distribution of the structure is relatively uniform.The hardness distribution of the sample of solution-aged parts is more uniform, and the solution aging can effectively increase the hardness of the bolt to meet the requirements of the material.