The high-temperature ablation and erosion behavior of MoSi2 coatings was systematically investigated through oxygen–kerosene combustion tests, simulating the extreme thermal and oxidative environment encountered in liquid rocket engine thrust chambers under high-temperature gas flow conditions containing entrained particles. Detailed surface analysis revealed distinct erosion features, including central pits, transitional zones, and particle accumulation areas, indicating complex thermomechanical and oxidative interactions. An erosion rate prediction model was developed, incorporating both normal impact-induced fragmentation and tangential shear effects of particle collisions. The model was validated against data obtained from oxygen–kerosene combustion tests, and demonstrated good predictive accuracy. These results provide valuable insights for the design and performance assessment of high-temperature protective coatings in aerospace propulsion systems.