▎ 摘　　要

Based on the first principles calculation, we studied the influence of single vacancy defects on the metallicity of metal graphene nanoribbons. The studies show that the metal bandwidth of the metal GNR is about five times that of the intrinsic GNR after the introduction of zero mode. The single vacancy defect is an effective strategy to modulate the metallicity of GNR, of which the metal bandwidth can be changed in the range of 27.81 meV-965.87 meV. The ability to modulate the metallicity with the defects at the edge of the GNR is better than that inside the GNR. The metal bandwidth is inversely proportional to the locality of the wave peaks at the Fermi level.