Abstract: Taking chopped PAN-based oxidized fiber and phenolic resin as raw materials, the low-density carbon-carbon composites were prepared by vacuum moulding technique, solidification, and carbonization process, and the microstructure and properties of the composites were studied by scanning electron microscopy and material testing. The result show that the composite had obvious anisotropy. The open porosity of the composite gradually decreased, while the density increased from 0.11 g·cm-3 to 0.22 g·cm-3, and the compressive strength raised from 0.18 MPa to 1.09 MPa with the decrease of the fiber content from 95wt% to 58wt%, and the mechanism of compression fracture also changed.