The invention relates to a high-molecular composite material having performances of high heat conduction and high flame retardation, the invention is characterized in that the composite material does not contain any halogen or a non environmentally-friendly heavy metal fire retardant, the flame resistance is capable of reaching a UL94 V0 standard, simultaneously, the composite material has good heat conducting performance, the heat conduction coefficient is more than 0.5 W / m. DEG C. The composite material provided in the invention has good injection moulding performance, extruding performance and hot pressing performance. The composite material comprises the following basic components: 1) one or a plurality of metal hydroxides, such as aluminum hydroxide, magnesium hydroxide, zinc hydroxide and the like, wherein the weight content is 10-70%, 2) about 0.2%-60% of the weight content of expandable graphite flaky powder, the lamina size is more than 10 um, and the expandable coefficient is more than or equal to 20 times; 3) 15%-70% of the weight content of matrix resins, such as epoxy resin, organic silicone resin, phenolic resin, thermosetting polyester resin and thermoplastic resins of nylon 6, nylon 66, PBT, PP, HDP and the like. The composite material component of the invention can be directly used for radiators such as LED, electric appliances and electronic components, the heat can be radiated into colder environment so that the operating temperature of the electronic device can be reduced.