Er³⁺-doped tellurite glass (TeO₂-ZnO-Na₂O) prepared using the conventional melt-quenching method is modified by introducing the SiO₂, and its effects on the thermal stability of glass host and the 1.53 μm band spectroscopic properties of Er³⁺are investigated by measuring the absorption spectra, 1.53 μm band fluorescence spectra, Raman spectra and differential scanning calorimeter (DSC) curves. It is found that for Er³⁺+-doped tellurite glass, besides improving its thermal stability, introducing SiO₂is helpful for the further improvement of the fluorescence full width at half maximum (FWHM) and bandwidth quality factor. The results indicate that the prepared Er³⁺-doped tellurite glass containing an appropriate amount of SiO₂has good prospect as a candidate of gain medium applied for 1.53 μm broadband amplifier.