Abstract: Carbon/carbon (C/C) composites have been widely used as ablative materials with excellent performance, it has great potential to be used as laser ablation resistant material. In this paper, C/C composites with different densities were prepared. CO₂ laser was used as the heat source to explore the interaction mechanism between high-energy laser and C/C composite material under oxygen-free atmosphere, and systematically analyze the influence of C/C properties and laser parameters on ablation performance. The ablation depth was characterized by 3D profilometer. The results show that the variation of C/C ablation behavior is nonlinear with the change of ablation time or laser power. Intrinsic properties of C/C composites determine the thermal load, which determines the ablative performance of C/C composites. When the laser heat flux is greater than the thermal load of the material, the linear ablation rate will rise drastically.