The invention provides a conductive adhesive for lithium ion batteries. The conductive adhesive comprises graphene and a first adhesive grafted to the surface of the graphene, and the first adhesive comprises at least one of polyvinyl alcohol, sodium carboxymethylcellulose, polyethylene glycol, polylactic acid, polymethyl methacrylate, polystyrene, polyvinylidene fluoride, hexafluoropropylene polymer, styrene-butadiene rubber, sodium alga acid, starch, cyclodextrin and polysaccharide. The conductive adhesive for lithium ion batteries has good conductivity and adhesive property, and is of certain strength, so that the integral mechanical strength of the electrode plate can be strengthened; the conductive adhesive realizes that the adhesive is combined with a conductive agent, so that the content of active substances in the electrode plate can be increased, and the energy density of cells is further increased. The invention also provides a preparation method of the conductive adhesive, an electrode plate containing the conductive adhesive and the lithium ion battery.