Abstract: WC-Cu based diamond bit matrix is widely used in deep drilling. To improve the service performance of diamond bit, orthogonal experiment method was employed to design the hot pressing parameters of the same matrix formula. Samples were fabricated to test their bending strengths and microhardness, respectively. The effects of sintering temperature A, sintering pressure B, holding time C and cooling type D on the physical properties of diamond bit matrix were studied by variance analysis and range analysis. Results show that the influence on bending strengths of pure matrix and diamond matrix is A>D>B>C, and that the influence on hardness of matrix is A>C>B>D. The best mechanical properties of matrix is obtained under A₃B₃C₁D₄, which is at sintering temperature of 960 ℃, sintering pressure of 16 MPa, holding time of 3 min and cooling mode of 400 ℃ within furnace. At this time, the blending strength of the pure matrix was 983.33 MPa, and its hardness was 437.40 HV, while the blending strength of the diamond matrix was 525.00 MPa.