Abstract: 6063 aluminum alloy was welded through solid-state diffusion bonding and transient liquid phase bonding,respectively. The microstructure near the diffusion interface was observed by metallographic microscope. The tensile strength of the joints was tested on universal testing machine. Test results show that solid-state diffusion bonding can obtain better joint performance than that of transient liquid phase bonding when connecting the same aluminum alloy. In the case of welding temperature 540 ℃,welding pressure 8 MPa and holding time 80 min,the composition of joint obtained by solid-state diffusion bonding is uniform without cavity defects. The tensile strength is 122 MPa,which is 94% of the base metal under the same heat treatment condition.