Abstract: The characteristics and mechanism of welding Al₂O_3p/6061aluminum matrix composite with direct diffusion welding and interlayer diffusion welding in low vacuum environment was investigated,and effects of temperature,holding time and other parameters on the performance of welded joints were analyzed.The results showed that there were three stages of the transform of joint strength with different temperature.At the longer holding time the higher strength could be gained.And at higher temperature,the oxide film was crumbled by pressure and liquid metal,and this improved the quality of welded joint.