10 wt% Nano-Al2O3 / 7075 aluminum matrix composites were prepared by powder metallurgy and hot extrusion. The effects of sintering temperature and extrusion ratio on microstructure, density, elastic modulus, hardness and compressive strength of the composites were studied. The results show that: with the increase of sintering temperature, the hardness of the composites with extrusion ratio of 4:1 and 8:1 increases at first and then decreases, and the overall hardness of the composites increases obviously; the compactness of the composites after extrusion is more than 98%; the compactness of the composites after extrusion is 4:1, the sintering temperature is 620 ℃, 630 ℃ When the extrusion ratio is 8:1, the compressive strength of the composite increases by 33.2%, 34.1% and 31.1%, which increases first and then decreases with temperature. In conclusion, the elastic modulus of the composites has little change.