The paper studies the influence of micro- and nanoparticles of metals and metal oxides on physicochemical properties of high-energy materials comprising cyclic nitroamine crystals. The micro- and nanoparticle encapsulation technique is developed for such cyclic nitroamines as 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20) and 2,4,6,8-tetranitro-2,4,6,8- tetraazaicyclooctane (octogen, HMX). Studied and analyzed are physicochemical properties of the novel high-energy materials comprising crystals of cyclic nitroamines. It is found that among the main parameters affecting the particle-size distribution in the crystals and the volume fraction of the metal inclusions, of critical importance is the stirring rate of the reaction mixture when distilling off the solvent. The low stirring rate leads to the formation of polycrystalline structures with the branched surface and multiple defects. Although the conditions of the CL-20 crystallization (solvent/precipitator ratio, temperature, a mixer type, distillation rate) are similar for different aluminum grades (ASD-6 and ALEXTM), the shape and size of the synthesized crystals strongly differ in both cases. The CL-20Alex crystal is characterized by the lower size (~100–150 μm), more tapered sides and greater number of the surface defects than crystals with other inclusions. This is probably because the effect from metallic particles acting as inoculating crystals.