Abstract: Cu-Sn-Ti active filler metal was selected to weld the diamond particles on the steel matrix.The organization features and phase compositions of the weld interface of solder alloy and diamond and were studied and the influences of brazing temperature on the interfacial structure and the bond strength were analyzed.The results show that solder alloy elements and diamond had chemical reaction in the process of brazing and compounds such as TiC, CuTi, and CuSn, were generated and the chemical metallurgical combination among Cu-based filler metal, diamond particles and the steel matrix were obtained.When the brazing temperature reaches to 880-930℃, soldered joints with good connection can be obtained.When the brazing temperature reaches to 900℃, the compound layer emerging on the weld interface is homogeneous, continuous, fine and close.At this moment, under the same grinding conditions, the abrasion weight loss of the brazed diamond specimen is very small, and the powerful bond of the weld interface is achieved.