▎ 摘　　要

NOVELTY - Composite dispersant comprises distilled water, nonionic surfactant, anionic surfactant and wetting agent; where the nonionic surfactant is Tween(RTM: Carbomer) composite, the anionic surfactant is hydrocarbyl sulfonate composite, and the wetting agent is an amide composite. USE - The composite dispersant is useful in preparing mixed electroplating solution. ADVANTAGE - The composite dispersant has better conductivity than other reinforced phase composite electric contact material, wear resistance, thermal conductivity, has good stability, after the graphene and metal composite, and has no problem of dielectric corrosion. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: preparing a composite dispersant comprising adding anionic surfactant and nonionic surfactant to distilled water with temperature t0 is 40-50° C, and stirring time T0 is 5-15 minutes, (ii) adding wetting agent to the mixture obtained in the step (i), supplementing distilled water, stirring for time t1 i.e. 5-15 minutes to obtain the composite dispersant, in the composite dispersant; a mixed electroplating solution comprising the composite dispersant, a silver-based aqueous solution and graphene, and the silver-based aqueous solution includes potassium cyanide and silver ions; and preparing a mixed electroplating solution comprising (i) preparing a silver basic aqueous solution, in the silver basic aqueous solution, the mass volume concentration of potassium cyanide is 90-200 g/l, and the mass volume concentration of silver ions is 15-50 g/l, and (ii) adding the composite dispersant and graphene into the silver base aqueous solution successively, and stirring and mixing to obtain a mixed electroplating solution, preferably the mixed electroplating solution, the volume ratio concentration of the composite dispersant is 15-45 ml/l, and the mass volume concentration of graphene is 1-20 g/l.