C/SiC composites were prepared by the hot-pressed sintering process with SiC powder, carbon fiber and phenolic resin as raw materials. The effects of sintering pressure, sintering temperature and carbon fiber content on the ablation resistance of C/SiC composites were investigated via a designed orthogonal experiment. The phase composition, microstructure and ablation resistance of the samples were characterized by X-ray diffraction, scanning electron microscopy and oxygen-acetylene ablative method. The results show that the dominant factor affecting the ablation resistance of C/SiC composites is sintering temperature, while the minor factor is carbon fiber content. Increasing the sintering temperature and hot pressing pressure can be beneficial to the densification of the sample. However, the excessive sintering temperature and sintering pressure can promote the diffusion of Si element into carbon fiber that does not favor the ablative performance. In addition, the introduction of excessive carbon fiber is not conductive to the densification of the sample, thus leading to the ablation resistance reduction. With the sintering temperature of 2 050 ℃, the hot pressing pressure of 20 MPa and the volume fraction of carbon fiber of 25%, the obtained samples exhibit the superior ablation resistance with a mass ablation rate of 2.0 mg/s.