Abstract: In order to improve the diilling effect of bit in hard and compact rocks, to reduce the cost of bit, a part of WC in the matrix of the traditional hot pressed tungsten carbide based diamond bit is replaced by Fe. Powder metallurgy method is used to make the matrix and test its performance. Through analyzing the testing results, effects of WC content and Fe content on matrix performances were discussed. Then, regression equations of matrix hardness and wear resistance were obtained respectively by regression analyses and the optimum matrix hardness, wear resistance and their corresponding matrix formula were also achieved through constrained nonlinear programming using Excel.