Abstract: A more comprehensive study has been made on the particle size of SHS SiC powder and its influencing factors. It has been found the particle size of SiC is mainly depended on the particle size of carbon powder regardless of the particle size of silicon powder. On this base,the reaction mechanism of Si+C has been outlined. With preheating SHS technology,by using preset detonator,the ignition apparatus in SHS reaction equipment can be cancelled,thus realizing industrial continous production.