▎ 摘　　要

NOVELTY - Preparation of nano fluid involves preparing composite solvent, adding graphene composite into the composite solvent, dispersing to obtain graphene suspension, adding surfactant to the graphene suspension and dispersing. The composite solvent is a mixture of water and alcohols. The graphene composite is the composite of high oxidation degree of graphene oxide and high reduction degree of graphene oxide. USE - Preparation of nano fluid (claimed). ADVANTAGE - The nano fluid has high thermal conductivity and excellent stability, and is not easy to freeze in winter, and can be used for a long time at temperature of 50-100℃.