Abstract: 6% Al₂O₃/Mo composite powder was prepared by sol-gel method. The powder was then used as raw material to prepare 6% Al₂O₃/Mo composite material by microwave sintering. The effects of microwave sintering temperature and sintering time on microstructure and properties of the composite material were studied, and the microwave sintering kinetics of the composite powder was also discussed. The results showed that the morphology of the powder was smoothly polyhedral and nearly spherical. The density and hardness of Al₂O₃/Mo composite material increased with the increase of microwave sintering temperature and sintering time, and reached 98.1% and 2.969 GPa, respectively, at the sintering temperature of 100 ℃ for 30 min. The densification mechanism of 6% Al₂O₃/Mo composite powder by microwave sintering was the result of volume diffusion and grain boundary diffusion. With the increase of sintering temperature, volume diffusion gradually dominated, and the activation energy of microwave sintering was 201.93 kJ/mol in the temperature range of 1 500~1 600 ℃. The research showed that microwave sintering was an effective method for rapid preparation of high density Al₂O₃/Mo composite material.