A novel composite, 3D C/SiC-Cu, which contained copper as transpiration agent, was designed and prepared. The influence of copper contents (2.18, 4.86, 6.53vol %) upon the mechanical and anti-ablative properties was investigated. The flexural strengths of three composites were over 450MPa, and fracture toughness over 15.0MPa•m1/2. After being ablated for 35 seconds in flowing oxyacetylene torch environment, the composites remained integral, and the flexural strength and strength retention ratio of the composite increased with the copper content increase. The maximum recession rate of the samples in oxyacetylene torch test was as low as 0.0490mm/s.