In order to improve the mechanical properties and ablation resistance of ultra-high temperature ceramic matrix composites, C/ZrC-SiC composites were fabricated by precursor infiltration and pyrolysis (PIP) process. Effects of the pyrolyzing process of zirconium silicon precursor resin on the properties of C/ZrC-SiC composites were investigated. The results showed that the pyrolyzing temperature of ZS precursor resin had great effects on the properties of composites. The mechanical properties decreased at high pyrolyzing temperature due to the damaging of carbon fiber while it also decreased at low pyrolyzing temperature due to high oxygen content. The prepared C/ZrC-SiC composites were tested by 2850 K arc wind tunnel test and the ablation rate was 8.75 ×10^-4 mm/s,which showed excellent ablation resistance.