Porous carbon fiber reinforced ceramic matrix composite is a good thermal insulation material with low thermal conductivity, light weight, which has a huge application prospect in aeronautics and astronautics field. But the material is easy to destroyed by oxidation erosion and ablation. Double-layer structure ceramic coating was designed, and the ZrB₂-SiC-glass internalScoating was prepared by slurry sintering method , the ZrB₂-MoSi₂-glass coating was prepared by atmospheric plasma spraying in the outer layer. The phase structure and microstructure of the coating were examined by XRD and SEM, and the coating was ablated by oxygen - acetylene flame. It showed that the sealing effect is better When the glass content of the inner coating is 30% and dense inner coating can be sintered at 1300 ℃ for 2h. Outer coating , with good adhesion the inner coating , was prepared by using optimized plasma spraying with good adhesion the inner coating. The anti-erosion performance is good when surface temperature is below 1500 ℃. Ablation oxidation formed a dense layer with SiO₂ as the filling phase, ZrO₂, ZrSiO₄ as the supporting phase, and the pores were sealed which effectively protect the matrix material.