In this study, we employed the CALYPSO structure searching method and density functional theory to systematically investigate the structural, electronic and spectral properties of a Ni-doped B20- cluster. The lowest energy structures of B20- and Ni B20- were obtained with the PBE0/6-311+G(d) level. The obtained structure of B20- is consistent with previous experimental and theoretical research reports. The Ni B20- cluster is composed of a nickel atom sandwiched by two B₁₀ monocyclic rings. Furthermore, the natural population analysis, the natural electron configuration and molecular orbitals were studied based on the lowest energy structures. The results show that charges are transferred from Ni to B atoms and strong spd hybridization occurs in the Ni and B atoms. Finally, we simulated the photoelectron spectroscopy, IR, and Raman spectra, and assigned the main vibrational peaks for further experimental investigation. This research presents a powerful reference for future experimental synthesis and characterization of nickel-doped boron-based nanomaterials.