The exceptional proprieties of gadolinium oxide (Gd2O3) enable wide applications as sensitized fluorescent material, optical additive, and especially neutron absorber material for nuclear industry or nuclear medicine. Herein, to address the challenge of manufacturing custom-designed Gd2O3 structures, we propose a new approach to fabricating the Gd2O3 structure by vat photopolymerization 3D printing. The preparation of printing feedstock, photo-curing parameters and post-processing were investigated thoughtfully. It was found that the printing feedstock was a typical non-Newtonian fluid. The optimal machine light intensity and exposure time were 6 (∼977 μW/cm2) and 3 s, respectively. After being sintered at 1600 °C for 2 h, the resulting sample reached a density of 58%, a bending stress of 40 MPa, and a flexural elastic modulus of and 20.219 GPa. The successful manufacturing of pure Gd2O3 was further evidenced by the SEM results and XRD pattern. The phase transition of Gd2O3 from cubic to monoclinic occurred around 1400 °C, leading to significant densification. Finally, a green mesh structure with a length of 10 cm was prepared, demonstrating the practical application potential in the neutron absorption and shielding.