Abstract: This paper concentrates on the measurement and analysis of laser ablation effect of particularly prepared aerospace material, polycarbosilane (PCS). Laser ablation experiment setup is designed and built, based on a continuous-wave high-power solid-state laser (CWHPSSL). Metal-shell samples with composite PCS are prepared. Then a group of laser ablation experiments are performed on those samples. They are processed by laser beam with thousands of W/cm2. The results, including the ablation morphology and temperature data, are shown and discussed. Temperature data give a good demonstration of the protection effect of composite coating, and in the meanwhile the minor-morphologies in the ablated region hint the principle of PCS laser-proof effect. After that, a theoretical investigation is carried out. Fourier equation of heat conduction is applied to modeling the temperature field during ablation process. The simulation provides a good explanation on the principle of laser-proof effect of PCS composite coating. The results demonstrate that, with the protection of PCS composite coating, kilowatt-level laser only results in hundreds of Celcius temperature increment of steel substrate.