Garnet is considered as a potential matrix for immobilizing high-level radioactive waste (HLW) because of its large actinide package capacity and chemical flexibility. Y_3-xNd_xFe₅O₁₂ (0≤x≤2) series yttrium iron garnet (YIG) samples was successfully synthesized by solid-state sintering method using Nd³⁺ to simulate trivalent actinides. The solubility limit of Nd in the YIG and the influence of Nd doping amount on the phase and microstructure of ceramics was studied. Then the chemical durability of Nd-doped yttrium iron garnet solidified body under different pH conditions was evaluated. The results show that the ceramics with x≤1.7 show homogeneous single YIG, but the ceramics with x≥1.8 exhibit coexistence of three crystal phases (YIG, NdFeO₃ and Fe₂O₃). The solubility limit of Nd³⁺ in the pure YIG is about 29.5% (in mass). As the amount of Nd doping increases, the density of the ceramics increases, the volume decreases, and the porosity decreases. The leaching experiment results show that the normalized leaching rate of the elements (LR_i) is 10^-6~10^-5g·m^-2·d^-1. LR_Y is smaller than LR_Nd, and the normalized leaching rate of the elements in acid leachate is slightly higher than those in neutral and alkaline leachates. The results indicate that YIG ceramics are a potential candidate form for trivalent actinides.