In this paper, A variety of non-stoichiometric (Ti, Nb)C_x PCD tool binders were prepared by mechanical alloying (MA) of TiC and transition metal Nb. The phase composition of the sintered composite was detected by X-ray diffractometer (XRD), and the composite was treated and analyzed by jade software. The fracture morphology of the composites was observed by scanning electron microscope (SEM), and the hardness and fracture toughness of the composites were measured by Vickers hardness tester. The results show that in the range of 1300 ℃ to 1700 ℃, the higher the sintering temperature, the higher the degree of solid solution of TiC and Nb. Under the same sintering temperature, the hardness of (Ti, Nb)C_x composite gradually increases with the increase of metal Nb proportion. Under the same metal Nb proportion, the higher the temperature, the higher the degree of solid solution of Nb and TiC. Among them, the mechanical properties of composite material (Ti, Nb) C_0.5 are the best, and the best hardness of (Ti, Nb) C_0.5 composite material is 23.0 GPa and the fracture toughness is 7.20 MPa·m^1/2 at 1600 ℃.