Nanodiamond prepared by detonation synthesis using explosives as the precursor exhibits serious agglomeration characteristics in non-polar medium such as clean oil. Mechanochemical measures were introduced to modify nanodiamond (ND) surface, improve its dispersion behavior and actualize suspension stability. Hyperdispersants's adsorption can be intensified with the participations of mechanical forces, and the main mechanism of hyperdispersant may lie in the steric stabilization of its adsorption layer founded on ND surface. After the deagglomeration and dispersion treatments, a suspension containing ND particles with the average diameter of around 55 nm can be prepared and it can be reserved for over 6 months without any sedimentation.