The invention provides a surface treatment method of a tire bead steel wire of a radial tire. The tire bead steel wire is successively treated by the following working procedures including chemical hydrochloric acid washing, electrolysis sulfuric acid washing, electroless copper plating, paintcoat coating and drying, wherein chemical copper plating solution is aqueous solution of copper sulfate, magnesium stearate, sodium ethylene diamine tetracetate, alkylol amine, sodium dodecyl benzene sulfonate, sodium hypophosphite, hydrazine hydrate, boracic acid, sodium 3,3'-dithiodipropane sulfonate, lecithin and starch acetate. A paint formula adopted by paintcoat coating comprises coumarone resin, hexakis methoxymethyl melamine, benzotriazole, chloride natural rubber, phenolic resin, nanosilicon dioxide dispersoid, chlorinated polyethylene, methylbenzene and acetone. According to the treatment method, adhesive force between the tire bead steel wire and rubber can be enhanced, the surface rubber adhesion ratio of the steel wire after bonding is improved, and steel wire preservation time is prolonged.