The method of producing of nano-dimensional silicon carbide by compressing in a cyclic chemical reactor is proposed. Pyrolysis is initiated in mixtures of monosilane and hydrocarbon with argon. The resulting product is examined by X-ray diffraction and electron microscopy. It is established that the powder contains crystallites of silicon carbide with an average size of 5–12 nm. It is shown that at certain ratios of precursor concentrations in argon, the formation of carbon nanoparticles and/or graphene coating on the surface of SiC particles is also possible. The method is technological and efficient, it can be used in the production of high purity silicon carbide nanopowders and other compounds.