Abstract: The development of compact nuclear reactors imposes extreme high-temperature environments on structural and shielding components, rendering traditional polymer-based and cement-based neutron shielding materials inadequate due to thermal degradation and dehydration. Ceramic materials, while thermally stable, suffer from inherent brittleness. To address these challenges, this study aims to develop a novel zirconia-toughened alumina (ZTA) based high-temperature resistant neutron shielding composite featuring a hierarchical interpenetrating network structure. This material is designed to achieve a synergistic combination of excellent mechanical toughness, thermal stability, and effective neutron moderation and absorption capabilities. An organic foam impregnation method was utilized to fabricate the porous ceramic framework. Polyurethane sponges were pretreated and impregnated with ceramic slurries containing α-alumina as the matrix, B₄C and Gd₂O₃ as functional absorbers, and ZrO₂ as the toughening phase. Three slurry formulations (A, B, and C) with varying ZrO₂ content were prepared. The impregnated sponges were then sintered at 1 250 ℃, 1 300 ℃, and 1 350 ℃ to obtain the rigid ZTA frameworks. Subsequently, a vacuum negative-pressure impregnation technique was applied to fill the porous ceramic skeleton with a boron-modified phenolic resin containing B₄C and Gd₂O₃ fillers. The final composite was obtained after a thermal curing process. Comprehensive characterizations, including X-ray diffraction, scanning electron microscopy, thermogravimetric analysis, compressive strength testing, and neutron shielding performance evaluation using a DT neutron generator, were conducted. The characterization results indicate that formulation B exhibits optimal rheological properties and solid content, ensuring a uniform and continuous ceramic coating on the sponge templates. The framework sintered at 1 250 ℃ shows the most superior compressive strength and structural integrity. Higher sintering temperatures lead to abnormal grain growth and induce severe microcracking due to the drastic tetragonal-to-monoclinic phase transformation of ZrO₂ during cooling. Among the prepared composites, the B15 formulation (framework B combined with phenolic resin doped with 15% B₄C and 15% Gd₂O₃) demonstrates outstanding thermal stability. The composite maintains structural stability up to 479.53 ℃ at a 10% mass loss threshold. Furthermore, the B15 composite exhibits exceptional neutron shielding efficiency. The total neutron shielding rate reaches 63.82%, and the thermal neutron shielding rate peaks at 94.26%, primarily attributed to the exceptionally high thermal neutron absorption cross-section of gadolinium and the optimized hierarchical distribution of boron. The incorporation of the ZTA ceramic system into the interpenetrating network structure successfully overcomes the inherent brittleness of porous ceramic frameworks. This study provides a systematic optimization of the fabrication process and confirms the feasibility of integrating toughened ceramics into multiphase composite systems. The developed hierarchical boron-containing composite presents a highly promising candidate for neutron shielding applications in advanced compact nuclear reactors and other extreme high-temperature environments.