The invention designs a composite material. The composite material comprises carbon-fiber perform, matrix carbon, filler and diamond-like carbon, wherein the matrix carbon is uniformly adhered on the carbon fiber of the perform to form the carbon-fiber perform with the matrix carbon; the filler fills the inside of the carbon-fiber perform with the matrix carbon and coats the outside of the carbon-fiber perform with the matrix carbon to form a semifinished product; the diamond-like carbon comprises a diamond-like carbon layer coated on the semifinished product; and the filler contains a Ti element, a Si element, a C element and a Mo element. The composite material has the advantages that a method of combining four processes of CVI, SI, RMI and PECVD to prepare a finished product with the advantages of high compactness, low thermal expansion coefficient and friction coefficient, high self-lubricating property, high thermal conductivity, oxidation resistance, thermal shock resistance, ablation resistance, wear resistance, high strength and toughness and the like; and simultaneously, the process is simple, the preparation period is short, the equipment requirement is low, the cost is low, net shaping can be realized and convenience is brought for large-scale industrial application.