The invention specifically relates to
silicon carbide powder and a preparation method thereof. According to a technical scheme, the preparation method comprises the following steps of: uniformly mixing 5-20 percent by weight of nano-
silicon dioxide or silica micro-
powder, 0.5-2.5 percent by weight of
carbon black or amorphous
graphite powder, 70-88 percent by weight of an
alkali metal chloride and 5-15 percent by weight of aluminum powder serving as raw materials; putting the uniformly-mixed raw materials into a tubular electric furnace, raising the temperature to 800-1,000 DEG C at the temperature raising rate of 4-10 DEG C per minute under the
atmosphere of
argon, and preserving heat for 2-10 hours; and putting an obtained product into
nitric acid of which the concentration is 2-5 mol / L for soaking for 3-8 hours, filtering, cleaning with deionized water till the pH value of a cleaning solution is 7.0, and
drying at the temperature of 110 DEG C for 8-24 hours to obtain
silicon carbide powder. The method has the characteristics of low
reaction temperature, simple process, controllable synthesis process, low production cost, and the like; and the prepared
silicon carbide powder has the characteristics of high
crystallization, high product purity, freeness from an impure phase and powder particle size of 50-200 nanometers.