Abstract: In order to meet the diffusion bonding of titanium alloy structure with high accuracy and strong performance, the pure graphite was used as the position limitation block, TA15 titanium alloy test blocks with various height dimensions were diffusion bonded at the process parameters of 920 ℃, 9800 N, and a holding time of 2 h, and the holding time is 2 hours, and the effect of the gap size between position limitation block and TA15 titanium alloy test block on deformation, microstructure and mechanical property of diffusion bonded joint. Results show that the gap size has great effect on the deformation of TA15 titanium alloy diffusion bonded joint. When the gap size increased from −0.05 mm to 0.2 mm, deformation amount of diffusion bonded joint increased from 0.16 mm to 0.42 mm approximately linearly with the size and amount of micro holes decreasing, when the tensile strength of joint increased to the level of base metal. When the gap size was 0.2 mm, well bonded joint was obtained with β phase distributing on the bond line intermittently, and the tensile strength reached to 962 MPa with the tensile test joint fracturing at base metal. Therefore, scheme of TA15 titanium alloy diffusion bonding through position limitation could control the deformation effectively and regularly. Based on the deformation behavior, titanium component could be bonded with high accuracy and high performance combined compensation design of the product structure.