ZrB₂-SiC-B₄C ultra-high temperature ceramic coatings were prepared on C_f/SiC substrate surface by slurry painting-sintering method.The effects of the mass fraction of powder filler,diluent in slurry and the sintering temperature on the microstructure,composition and phases of ZrB₂-SiC-B₄C coating were studied.The results indicate that a dense and well-bonded ZrB₂-SiC-B₄C coating can be obtained on C_f/SiC substrate surface when the mass ratio of powder to resin is 1∶1,the mass ratio of diluent to resin is 1∶2,and the sintering temperature is 1 500 ℃.This coating has uniform phases,low surface roughness of Ra<1 μm,low porosity of around 4.2%,and high average tensile shear strength of about 5.4 MPa.After isothermal oxidation at 1 500 ℃ for 30 h,the weight loss of ZrB₂-SiC-B₄C coated C_f/SiC composite is around 10.7%.An intact ZrO₂-SiO₂ film is formed during the oxidation,which provides the effective anti-oxidation protection.Thus,the ZrB₂-SiC-B₄C coated C_f/SiC composite can be a candidate material for applications in the high temperature combustion flow environment.