The invention provides a method for developing high-performance heat-conducting oil with narrow-fraction C<10+> aromatic hydrocarbon as a raw material. The invention aims to solve the problems of reduced cetane number, unideal economic benefits and the like when the fraction C<10+> is applied to production of diesel oil in the prior art. According to the invention, C<10+> aromatic hydrocarbon reacts with an alkylation reagent to synthesize liquid aromatic hydrocarbon resin, and the liquid aromatic hydrocarbon resin is subjected to further chemical conversion, rectification and separation so asto obtain the high-value-added high-temperature heat-conducting oil base oil, so the utilization rate of heavy aromatics is increased, and resource waste is reduced. The method has the advantages ofsimple process, simple operation, cheap raw materials, and easy realization of industrial production.