${\mathrm{Tb}}_3{\mathrm{Ga}}_5{\mathrm{O}}_{12}$ (TGG) is an excellent material for magneto-optical applications, and is the key component in Faraday isolators (FIs). The preparation process of transparent TGG ceramics is experimentally studied. The optical quality and the microstructure of the samples are investigated. The results show that the transmittance of the sample sintered at 1550°C is close to 72% in the region of 500–1500 nm. The Verdet constant at 632.8 nm measured at room temperature is $125.01\mathrm{rad}{\mathrm{T}}^1{\mathrm{m}}^1$, which is almost the same as that of a single crystal.