Abstract: The single-walled carbon nanotubes（SWCNTs）/7075 aluminum matrix composites were prepared by ultrasonic dispersion, high-energy ball milling and discharge plasma sintering. The effects of different SWNTs contents on the microstructure and mechanical properties of 7075 aluminum alloy were studied. The results show that with the increase of single-walled carbon nanotubes, the grain size of the composites decreases first and then increases, and the strength and hardness of the composites increase first and then decrease. When the mass fraction of single-walled carbon nanotubes is0.2wt%, the grain size of the composite reaches the minimum and the most uniform, and its strength and hardness also reach the maximum, which are 415.2 MPa and 142.94 HV0.1, respectively, which are 1.67 and 1.42 times of the matrix material.The main strengthening mechanism is dispersion strengthening of the second phase, which mainly consists of single-walled carbon nanotubes and Mg（Zn, Al, Cu）₂.