Boron-based nanomaterials have attracted significant attention in cluster science due to their unique molecular structures and chemical bonding. In this study, we systematically investigated the structures and properties of M₂ (M=Li, Na, K) doped B0/ ?18 clusters at the PBE0/6-311+G(d) level using the CALYPSO structure prediction program combined with density functional theory. Structure predictions found that all doped systems exhibit tubular configurations. Except for Li₂B₁₈, which has C1 point group symmetry, the global minimum structures of the other clusters adopt a D_9d point group symmetry tubular shape, with the two M atoms localized along the axis of the tubular structure. Stability analyses indicated that K₂B₁₈ and Li₂B?18clusters exhibit relatively strong stability in the neutral and anionic series, respectively. Charge transfer analysis revealed that electrons are transferred from the M atoms to the base boron fragment. Magnetic properties analysis indicated that the total magnetic moment is zero for the closed-shell structures of Li₂B₁₈, Na2B18 and K₂B₁₈ clusters. However, the open-shell structures of Li₂B?18, Na₂B?18 and K₂B?18 clusters exhibit magnetic moments of 1 μB. Dipole moment and polarizability analyses showed that both the dipole moment and the first hyperpolarizability are zero for the highly symmetrical structures. Additionally, simulated photoelectron spectra, IR spectra and Raman spectra, generated using Multiwfn software, provide a theoretical basis for further experiments. At last, the relationships between thermodynamic parameters (C_v and S) and temperature were discussed.