The invention relates to a synthesis and preparation method of a composite material applied to a positive intercalation of a lithium-sulphur battery, and in particular relates to a preparation method and application method of a graphene/titanium oxide composite material. The preparation method comprises the following steps of mixing and dissolving titanium oxide and graphene in an organic solvent to form slurry, and coating the surface of a lithium-sulphur positive material with the slurry. The preparation method is simple to operate and low in cost; furthermore, shuttle effects of polysulfide ions in the lithium-sulphur battery can be effectively inhibited; and the capacity and the cycling performance of the battery are greatly increased.