Abstract: Through numerically simulating the temperature field in a multi-heat-source synthetic SiC furnace, the temperature distribution at characteristic points was obtained, and the dynamic laws of thermal gradient and thermal flow intensity were put forward. The heat and mass transfer law in multi-heat-source synthesis of silicon carbide were revealed. It was shown that due to the superposition effect of thermal fields and the shielding action of furnace cores, the SiC output of the multi-heat-source furnace increased by 48.1% compared with that of an Acheson singleheat-source furnace, the highest grade SiC increased by 30%, and the consumed energy reduced more than 10%. In addition, the frequent spouting was diminished, and the furnace was become more productive and safe.