Abstract: The Gd-doped monazite-Ce ceramic forms were prepared by hot-pressing using Ce₂(C₂O₄)₃•10H₂O, NH₄H₂PO₄ and Gd₂O₃ as raw materials. The hot-pressing sintering and chemical durability of the ceramic forms under the coupling effect of thermodynamics-hydrodynamics-mechanics-chemistry (THMC) were investigated by means of XRD, FESEM, EDS, ICP-MS and so on. The results show that the single monazite-type Ce_0.9Gd_0.1PO₄ phase is obtained by hot-pressing at 1150-1200 ℃ for 2 h. The relative density of the ceramic form is 99.62%. Furthermore, the ceramic forms exhibit excellent chemical durability under the coupling effect of THMC (90-200 ℃ (0.101-1.554 MPa), pH=5.9). The normalized leaching rate (LR) of Gd is 10^-6-10⁵ g/（m²•d） orders of magnitude on the 42nd day. Both leaching temperature and pH value have little influence on the LR of Ce, while the leaching temperature has no effect on the LR of Gd. The LR of Gd is relatively higher in weakly acidic (pH=5) and neutral (pH=7) water solution than that in weakly alkaline (pH=9) water solution.