The Cu-Sn binary intermetallic powders were obtained via a patented reaction ball milling technique. The Sn melt reacted with the solid-state Cu during the milling process at different temperatures for different intervals. Two kinds of binary intermetallics were obtained. For 12 h,Cu6Sn5 was prepared by milling Sn melt at 573 K while Cu3Sn by milling Sn melt at 773 K. And a mixture of Cu6Sn5 and Cu3Sn was fabricated at 673 K. All these intermetallic powders had mean grain sizes of less than 100 nm. A finer microstructure was obtained by milling Sn melt blended with 20%(mass fraction) Ni powders at 573 K for 12 h. The reaction mechanism and advantages were discussed in comparison with that of high-energy ball milling. The results show the solutionizing of Ni powders in the Cu6Sn5 intermetallic.