In this work, to improve the ablation resistance and oxidation performance of carbon fiber-reinforced carbon matrix (C/C) composites widely applied as aerospace high-temperature structural materials in an oxidizing environment above 2000℃, C/C-SiC-ZrB2-ZrC composites were fabricated by hybrid processes of ZrB2 slurry impregnation, ZrC-SiC precursor infiltration-pyrolysis and reactive melt infiltration with a Si-Zr10 eutectic alloy. The matrix microstructure and the evolution mechanism of the prepared composites were investigated in detail by phase composition, microstructure analysis, model experiments, and thermodynamic calculation. The mechanical properties and ablation resistance of the composites were tested by three-point bending tests and an atmospheric plasma torch, respectively. The results showed that in the cooling stage after infiltration, in situ solid-liquid reaction between ZrC ceramics and residual Si melt resulted in the formation of ZrSi2 and SiC, characterizing as such submicron SiC particles evenly embedded in the ZrC-ZrSi2 binary phases and finally generated a ZrC-ZrSi2-SiC complex micro-region. The obtained composites with a density of 3.18 g/cm3 and an open porosity of 2.77% showed a flexural strength of 121.46±13.77 MPa and a flexural modulus of 21.78±5.56 GPa. Moreover, numerous fibers were pulled out and obvious interfacial debonding was observed in the fracture section, indicating that the failure mode of the composites was a ductile fracture. After plasma-arc ablation at 2000℃ for 300 s, the C/C-SiC-ZrB2-ZrC composites exhibited excellent ultra-high temperature ablation behavior. The mass and linear ablation rates were 1.37×10-3 g/s and 3.43×10-3 mm/s, respectively. It was found that a unique double-layer oxide structure was formed in the ablation center. The ZrO2 layer as the inner layer can inhibit heat conduction into the internal matrix to further improve the high-temperature resistance of the composites. The composite oxide layer composed of solid-phase ZrO2 particles and liquid-phase SiO2-ZrO2 melt rich in SiO2 as the outer layer can not only resist mechanical scouring of high-speed gas flow but also inhibit the inward oxygen diffusion.