Carbon nanotubes (CNTs) reinforced aluminum-based composites exhibit characteristics such as low density, high specific strength, and high specific stiffness, making them promising materials for applications in aerospace, automotive lightweighting, and other fields. The dispersion of CNTs in the aluminum matrix and the strength of the interface between CNTs and the aluminum matrix are crucial for the preparation of CNTs reinforced aluminum-based composites. In this study, CNTs were surface-modified with partial coating of Al2O3, and then the CNTs reinforced 2195 aluminum-based composite (2195/CNT composite) were prepared using a combination of melting-casting process and hot extrusion. The tensile strength, yield strength, and elongation of the aged 2195/CNT composite reached 697 MPa, 590 MPa, and 11.3 %, respectively, demonstrating a significant improvement in mechanical properties compared to 2195 alloy prepared under the same conditions. CNTs were primarily present at grain boundaries, and a small amount of glow stick-like Al4C3 phase was found near the CNTs. The formation of glow stick-like Al4C3 phase was attributed to the segregation of solute elements at the interface in the alloy. First-principles calculations revealed that solute elements tended to segregate at the interface closer to the aluminum matrix. Moreover, the segregation of Cu and Ag elements at the interface could enhance the cleavage energy of the Al4C3/Al interface, while the segregation of Mg elements reduced the cleavage energy of the interface. This study also analyzed the reinforcement mechanisms involved in the 2195/CNT composite.