The invention discloses a graphene structure adhesive for wind-power blades and a preparation method thereof. The graphene structure adhesive is prepared by combining a resin part and a curing agent part according to the weight ratio of 40 to 50. The resin part is prepared from, by weight, 40-70 parts of E51 epoxy resin, 0-20 parts of bisphenol F epoxy resin, 2-6 parts of 1,6-hexandiol diglycidyl ether, 5-10 parts of gas-phase silica, 15-30 parts of calcium carbonate and 0-3 parts of graphene, the curing agent part is prepared from, by weight, 20-40 parts of polyether amine, 20-40 parts of polyamide, 10-20 parts of isophorone diamine, 5-10 parts of gas phase silica, 15-30 parts of calcium carbonate and 0-3 parts of graphene. The weights of the graphene raw materials of the epoxy resin part and the curing agent part cannot be 0. The graphene structure adhesive can simultaneously give consideration to excellent structural strength, toughness and curing heat-effect performance.