Abstract <p>FCC plate-lattice metamaterials are a class of novel metamaterials with excellent mechanical properties. The existing researches mainly focuses on their mechanical performances, while the thermal insulation performance is crucial if the FCC plate-lattice metamaterials are applied into thermal protection structures. Based on the numerical simulation and orthogonal experimental methods, the influence mechanisms of structural geometric parameters on the effective thermal conductivity and local maximum thermal stress are investigated for the FCC plate-lattice metamaterials in this study. A theoretical equivalent thermal conductivity model is established for unit cells with two different perforation forms, and validated by the numerical simulation results. It can be found from both numerical and theoretical results that reducing plate thickness, increasing pore radius, and increasing edge length are beneficial for improving the thermal insulation performance. Properly increasing the pore radius, reducing the plate thickness, and restricting the tetrahedral element size can reduce the maximum thermal stress and improve the structural durability. Under the same relative density, the FCC plate-lattice with pores at vertices exhibits better thermal insulation performance than the FCC plate-lattice with pores in the panel, while the FCC plate-lattice with pores in the panel has more concentrated data points, enabling accurate prediction of the structure’s thermal insulation performance.</p>