With the rapid development of laser technology, ablation damage caused by high-energy lasers has become a critical issue in the design of aircraft thermal protection systems (TPS). To reveal the laser ablation mechanisms of carbon-based thermal protection materials under high-speed airflow, this paper establishes a tightly coupled multi-physical field numerical model applicable to high-speed flow conditions. The model comprehensively accounts for multiple ablation mechanisms, including material oxidation, sublimation, and mechanical erosion, while incorporating transient wall recession induced by ablation and interspecies reaction processes, thereby enabling accurate simulation of the laser ablation process. A blunt-wedge configuration is selected as the test case, and numerical simulations of laser ablation are conducted under a freestream Mach number of 24. The results indicate that, within the laser-ablated region, the temporal evolution of wall temperature at different locations exhibits similar trends, characterized by a rapid increase during the initial stage followed by a gradual stabilization. The influence of laser loading on the temperature field is primarily confined to a localized region, while the ablation products are continuously entrained into the main flow, leading to thermal energy accumulation within the boundary layer and downstream diffusion along the flow direction. As the ablation process develops, the morphology of the high-temperature region evolves from an initially localized “spherical” shape into an elongated “tongue-like” structure stretched along the wall, exhibiting pronounced convective–diffusive characteristics. In addition, a distinct “high-pressure core” forms in the near-wall region of the ablation pit, accompanied by a pair of corresponding compression and expansion wave packets on both sides of the cavity. The local pressure distribution exhibits clear spatial characteristics, indicating that the closer to the central spanwise plane, the stronger the influence of pit evolution on the near-wall pressure field, and vice versa.