The present invention relates to a method for preparing a carbon-based particle/copper composite material in which carbon-based particles such as graphite and copper are mixed, the method including mixing a solution of a polymer organic compound having a main chain of carbon and a copper precursor in a solvent, with a dispersion solution of carbon-based particles in a first dispersion medium to produce a mixture, adding a first reducing agent to the mixture to form composite particles in which copper (I) oxide particles are attached to the surface of the carbon-based particles, and sintering the composite particles under a non-oxidizing atmosphere. According to the preparing method, a composition material is obtained, in which carbon-based particles and copper are well mixed.