The invention relates to nano composite materials and especially relates to a nano indium oxide/carbon composite material and a preparation method of same. In the invention, various carbon materials are used as substrate materials; one or a mixture of more than one of indium nitrate, indium chloride, indium sulfate and indium acetate are used as an indium raw material; one or a mixture of more than one of water, ethylene glycol and propylene glycol, which contain a complexing agent, are used as a solvent; a nano indium oxide/carbon composite is prepared through adsorption-thermal treatment process; then the nano indium oxide/carbon composite is subjected to the adsorption-thermal treatment process again to obtain the nano indium oxide/carbon composite material which is high in indium oxidesupporting quantity. The method is simple, has short process and high efficiencyand is free of special equipment and additional cost. In the composite material, the indium oxide particles are uniformly distributed on the surface of carbon particles in nano dimension.