Abstract: In light of light thermal protection materials’ anti-ablation difficulty in deep space with higher heat flux, the ablation properties of light thermal protection material A enhanced by honeycomb (self-developed with a density of 0.48 g/cm³) was researched by arc-heated wind tunnel test (with a heat density of 6 000 kW/m²). The density change analysis of the material after ablation was done along the depth direction. The thermal stress of material A was calculated and analyzed. Research results show that the carbonization layer is complete after ablation; it can be clearly seen from the micro graph of the carbonization layer that hollow fillers are broken and the resin matrix cannot be seen; the components of the material react with each other and SiC crystal is generated on the surface of material A, which boosts heat consuming in the processing of ablation and improves the carbonization layer strength and retards oxization. The thickness of pyrolysis layer is thin, which shows that the light thermal protection material has excellent insulation performance. The honeycomb structure of material A can effectively reduce the thermal stress of the material. This research has great significance for the reliability assessment of thermal protection materials in deep space exploration.