Aluminum matrix composites (AMCs) reinforced by Ti3C2Tx are receiving increasing attention. However, the key constraints to its application breadth are the poor thermal stability and its poor interfacial bonding with aluminum (Al). In this paper, the surface modification of Ti3C2Tx is carried out by chemical Ni coating, and the effects of such reinforcement on the microstructure and interfacial architecture, as well as the mechanical properties of the Al6061 composites before and after Ni-coated are compared. The results show that Ni-coated Ti3C2Tx improves its dispersion in the Al melts and blocks the interfacial reaction between Al and Ti3C2Tx. HRTEM analysis shows that the dense Ni nanoparticles on the surface of Ti3C2Tx optimize its interfacial structure with Al. The mismatch of (102)Al3Ni//(1−11)Al is 4.3 %, indicating that the Al6061–2.5 wt% Ti3C2Tx@Ni (AT2.5@Ni) composites are strengthened by the form of Al3Ni-Al interfacial coherence. The yield strength, tensile strength, and elongation of AT2.5@Ni composites are 122.1 MPa, 223.4 MPa, and 5.2 %, which are 53.0 %, 57.9 %, and 2.0 % higher than that of Al6061 matrix, respectively. The better mechanical properties are mainly attributed to the strong Ti3C2Tx-Ni-Al3Ni-Al interfacial architecture formed in the composites, resulting in the effective load transfer from matrix to Ti3C2Tx.