Abstract: The matrix and diamond tool materials were prepared by pressureless sintering, using FeCoCu pre-alloyed powders as the main matrix materials and CuSn₁₅ pre-alloyed powders as the additive. The effects of CuSn₁₅ content on the mechanical properties, diamond holding power, and microstructure of the matrix and diamond tool materials were investigated. The bonding interface between the diamond and the matrix metal was analyzed after adding CuSn₁₅, and the influence of chemical bonding, mechanical insertion, and the supporting force between the matrix and diamond particles on diamond holding power was discussed. The results show that with the increase of CnSn₁₅, the relative density, hardness, and bending strength of the FeCoCu matrix increase first and then decrease. The mechanical properties of the FeCoCu matrix with the CuSn₁₅ mass fraction of 8% are better, the relative density, hardness, and bending strength are 97.5%, HRB 104.6, and 1112.6 MPa respectively. The strength loss rate of the FeCoCu matrix with 8% CuSn₁₅ is 21.7%, which indicates that the matrix has a good holding power for the diamond tools.