In this paper, carbon nanotube/aluminum composites were successfully prepared by taking advantage of the large specific surface area of flake aluminum powder using the flake powder method, and low structural damage to carbon nanotubes and good dispersion in an aluminum matrix were achieved. However, the natural existence of aluminum oxide film on the surface of aluminum powder prevented the direct bonding of carbon nanotubes and aluminum. Due to the low preparation temperature of powder metallurgy, it is difficult to form a strong chemical bond between the carbon nanotube, oxide and aluminum, and the composites are directly destroyed at the mixed interface after tensile testing, resulting in a decrease in the strength rather than an increase compared with the matrix alloy. By increasing the thickness of the flaky aluminum powder to reduce the oxide on its surface and combining it with the addition of magnesium, the interfacial bonding strength is greatly increased, and the yield and tensile strength of the composite are significantly improved compared with those of the matrix.