The Al_2O_3 - SiC composite powders were prepared in argon atmosphere using coal gangue and carbonaceous materials < carbon black,active carbon and anthracite) as starting materials by carbothermal reduction. Effects of excessive carbon addition,carbon types, temperature,soaking time,shaping pressure,types and amount of additives on phase composition and microstructur e of the Al_2O_3 -SiC composite powders were investigated. The results indicate that:temperature,soaking time and chloride additive have significant influence on the synthesized Al_2O_3 - SiC composite powders.Based on the results,the optimized Al_2O_3 -SiC composite powders (Al_2O_3 58 mass%and SiC 42 mass%) with particle size d_(50)≤5μm were prepared using coal gangue and carbon black as starting materials after 3 h firing at 1 550℃.and proper additive addition could reduce the temperature by 50℃. The Al_2O_3 - SiC composite powders were prepared in argon atmosphere using coal gangue and carbonaceous materials