<p>First-principles calculations within the framework of density functional theory are employed to investigate the structural, mechanical, electronic, optical, and thermodynamic properties of the theoretically proposed MAX-phase compounds M₂CrSnC₂ (M = Zr, Nb, Mo). Structural optimization confirms a stable hexagonal crystal structure, with a systematic increase in lattice stiffness from Zr to Mo, as evidenced by bulk moduli of 173.44, 214.25, and 234.22 GPa, respectively. Negative formation energies and well-converged Birch–Murnaghan equations of state establish the thermodynamic and structural stability of these phases. The calculated elastic constants satisfy the Born stability criteria, revealing a transition from relatively brittle behavior in Zr₂CrSnC₂ to enhanced ductility in Nb- and Mo-containing compounds. Electronic band structures and density of states indicate metallic conductivity dominated by transition-metal d states at the Fermi level. Thermodynamic analysis shows that the heat capacity approaches the Dulong–Petit limit at elevated temperatures, while Debye temperatures remain highest for Mo₂CrSnC₂, reflecting stronger lattice rigidity. The lattice thermal conductivity exhibits a pronounced temperature dependence, decreasing rapidly due to enhanced phonon–phonon scattering. The calculated properties suggest potential applicability in high-temperature structural and conductive coating materials.</p>