Abstract: With matrix materials for hot pressing sintered diamond segment as the object in this study, the authors analyzed the effect of FCu14 pre-alloy powder on the performances of diamond segment from different formulation. The results showed that, with the increase of FCu14 pre-alloy powder content,matrix alloy composition gradually becomes uniform. Tiny iron-based matrix is surrouded evenly by copper-based binder, reducing the presence of pores. Because porosity of matrix significantly uniform and refinement, porosity was reduced greatly, the matrix hardness gradually increased. A decreasing of porosity makes the fragmentation of it on matrix reduction. The corresponding microdefect in material is also little, making the shear strength and bending strength increased. However, excessive dosage will make the matrix too large, resulting in significant decline in the toughness of the matrix and an increase in brittle, that will make the number of dimples in the fracture decreased rapidly. So its strength will be reduced accordingly.