The invention relates to a method of synthesis of nano SiC by laser pyrolysis. According to the invention, the method consists in the laser pyrolysis with linear ignition and the combustion/decomposition of precursors silane/acetylene by the punctual/linear flame initiation for the synthesis of silane, materialized along the optical axis of the laser beam focused at a convenient geometry and at a power density required by the synthesis, in a reaction chamber, with a flame propagation in the gas flow direction, towards the collector, until they are cooled together with the SiC nanoparticles obtained by the synthesis.