Abstract: The pre-mixed filler metal is made by adding Fe, Al and Si elements in the Cu-Sn-Ti pre-alloy filler metal. 17 kinds of proportioning schemes are determined by using the extreme vertex mixture design method with both upper and lower bounds. The mechanical properties of the solders were evaluated by the shear test. The interface of the matrix, the morphology of diamond and the interface of diamond were analyzed by SEM, EDS and Raman. The test results show that the shear strength of the pre-mixed filler metal decreases obviously when the mass fraction of Cu-Sn-Ti is below 95%, and the mass fraction of each addition should be under 2%. The premixed solder made of Fe, Al, Si with the same mass fraction of 1.7% added in Cu-Sn-Ti have better comprehensive performance, the melting point and the flow ability are suitable, the abrasive grain edge is good, the diamond is not damaged and the dendritic compact TiC is formed on the interface of diamond.