The invention discloses a nanometer
diamond polishing solution and a preparation method thereof. The nanometer
diamond polishing solution is prepared from the following components in percentage by weight: 0.5-5 percent of modified nanometer
diamond, 4-10 percent of
polyol surfactant, 0.1-2 percent of dispersant, 0.02-1 percent of
corrosion inhibitor and the balance of pH
regulator and water, wherein the modified nanometer diamond is obtained by
grafting the surface of nanometer diamond
powder with carboxyl groups. For the nanometer diamond
polishing solution and the preparation method providedby the invention, the modified nanometer diamond is grafted to the
polyol surfactant, so that the modified nanometer diamond is stable in dispersion, ensures the polishing accuracy and remarkably lower the risk that the polishing surface is scratched; in addition, the modified nanometer diamond is difficult to separate the polishing solution, so that the phenomenon that particles fall off to cause the
chip cutting speed to drop rapidly and formation of black points on the polishing surface are avoided; and in addition,
sedimentation can not occur among the modified nanometer diamond althoughflocculation occurs, and the nanometer diamond polishing solution has the reparability ability and can be applied to the finish polishing field of magnetic heads, artificial crystals, gemstones and the like.