Abstract: The vacuum brazing of polycrystalline diamond and oxygen free copper(OFC) using AgCuTi brazing material was conducted. The effects of brazing temperature (830 ℃, 870 ℃, 910 ℃, 950 ℃) and holding time (1、10、30、60 min) on the interface structure and mechanical properties of the joint were studied, and the mechanism of interface formation was elucidated; the typical interface structure of brazed joints is diamond/TiC/Cu (s, s), Ag (s, s)/OFC; the brazing temperature has a significant impact on the microstructure of the brazed joint. When the temperature is above 910 ℃, the mutual dissolution and diffusion phenomenon between AgCuTi brazing material and OFC substrate is obvious; the shear strength first increases and then decreases with the increase of temperature, the highest shear strength of the brazed joint is 223.7 MPa, which is maintained at 870 ℃ for 10 minutes; finally, the fracture location and morphology of the brazed joint were discussed.