The localized surface plasmon can be directly excited by light in free space. This is also the advantage of local surface plasmon. So, it is very meaningful for us to study enhancement effect of erbium ion luminescence by surface plasmon of silver nanoparticles in bismuth luminescent glass, to further improve the luminescent properties of erbium ions. First, this paper measured the absorption spectra of (A) Er3+(0.5%)Ag(0.5%): BiSiGa glass and (B) Er3+(0.5%): BiSiGa glass sample. It was discovered that there is a weak broad resonance absorption peak of silver surface plasmon in the position of about 600 nm for (A) Er3+(0.5%)Ag(0.5%): BiSiGa glass. It was also found that both have typical absorption peaks of erbium ions. Their absorptions were almost exactly the same. They were similar in peak shape, peak intensity and peak wavelength. Second, we measured the excitation spectra of (A) Er3+(0.5%)Ag(0.5%): BiSiGa glass and (B) Er3+(0.5%): BiSiGa glass sample. Five visible excitation peaks, in the positions of 379.0, 406.0, 451.0, 488.0 and 520.5 nm respectively, have been found when monitored in 550.0 nm visible light. Same, eight infrared excitation peaks, in the positions of 379.0, 406.5, 451.0, 488.5, 520.5, 544.0, 651.5 and 798.0 nm respectively, have also been found when monitored in 1 531.0 nm infrared light. It was easy to identify them as the absorption peaks of 4I15/2→4G11/2, 4I15/2→2H9/2, 4I15/2→(4F3/2, 4F5/2), 4I15/2→4F7/2, 4I15/2→2H11/2, 4I15/2→4S3/2, 4I15/2→4F9/2, and 4I15/2→4I9/2 of Er3+ ions in turn. It is discovered by measurement that the maximum enhancement of visible and infrared excitation spectra was 238% and 133% respectively for (A) Er3+(0.5%)Ag(0.5%): BiSiGa glass relative to (B) Er3+(0.5%): BiSiGa glass. Finally we measured the luminescence spectra. Three sets of visible emission peaks at 534.0, 547.5 and 658.5 nm were found. It was easy to identify them as fluorescent transitions of 2H11/2→4I15/2, 4S3/2→4I15/2 and 4F9/2→4I15/2 of Er3+ ions in turn. It was also found that the infrared emission peaks were at 978.0 and 1 531.0 nm. They were fluorescence transitions of 4I11/2→4I15/2 and 4I13/2→4I15/2 of Er3+ ions in turn. It was discovered by measurement that the maximum enhancement of visible and infrared luminescence spectra was 215% and 138% respectively for (A) Er3+(0.5%)Ag(0.5%): BiSiGa glass relative to (B) Er3+(0.5%): BiSiGa glass. For the mechanism of erbium ion emission enhanced by silver surface plasmon, we think it is mainly that local surface plasmon resonance of silver nanoparticles causes the fact that the local electric field intensity generated near the metal nanostructure is much stronger than the electric field intensity of the incident light. This leads to metal nanostructures generating extremely strong absorption and scattering for incident light. This leads to enhance fluorescence. This is just the field enhancement effect of the local field of local surface plasmon resonance.