Abstract: GH4169 superalloy was bonded to itself by vacuum diffusion bonding with Ni interlayer. The effect of process parameters on the interface structure and mechanical properties of the joints was investigated. The bonding holes in the interface were used as the evaluation indicator. The experimental results without Ni interlayer show that,with the increase of heating temperature,diffusion time and diffusion pressure,the number and size of bonding holes in the interface decreased. When the bonding temperature was 1 100℃,the bonding time was 90 min and the pressure was 40 MPa,the diffusion holes almost disappeared,and the average tensile strength reached 658 MPa. With Ni interlayer,the briquettability of the joint was improved and the average tensile strength apparently increased. When the bonding temperature was 990℃,the bonding time was 75 min and the pressure was 15 MPa,the average tensile strength reached 840 MPa.