Using TNT/RDX as starting material, black powder containing nanodiarnond were synthesized successfully by explosive detonation under water, which were purified by oxidation with acids in liquid in order to obtain nanodiamond. The output of product to explosive was 5.2%. The black powder and nanodiamond powder were investigated with methods of XRD, TEM, SEM, FTIR, EPR, DTA and TG to characterize their morphologies, size, thermal property, functional groups and free radicals density on the surface.Effect of surface modification of stearic acid and five types of titanate coupling agents to black powder were compared by measuring contact angles. The results showed that titanate coupling of NDZ-311 possessed the optimum effect and the optimum content of the agent was 3.0%. The results of relevant analysis indicated the modified black powder was provided with higher dispersity and better hydrophobic ability than bare ones.The nanocomposites were prepared by low filling black powder to HDPE(High-Density Polyethylene) and LLDPE(Linear Low-Density of Polyethylene), the structures and properties of composites were studied. Investigation on mechanical properties of composites showed the mechanical properties of polymers filled with modified black powder were improved yet that filled with bare black powder were decreased. The friction and wear behaviors of the composites were examined on an MM 200 ring on block wear tester. The morphologies of worn surface were examined with scanning electron microscope (SEM). It was found that modified black powder can reduce the friction coefficient and wear mass loss of polymers significantly. With increase of the content of black powder, the friction properties were gradually improved. Considering the mechanical properties and cost, the optimum content of black powder was selected for HDPE and LLDPE, respectively. Moreover, the effect of test loads on friction and wear mass loss of the composites were studied in this paper.