The invention discloses an anti-corrosion treatment method of a workpiece for manufacturing a guardrail. The anti-corrosion treatment method comprises the steps that the workpiece is subjected to wiredrawing treatment, and line patterns are formed on the surface of the workpiece; the workpiece is completely immersed into a pickling solution, the pickling time is 20 to 30 minutes, and dirt and impurities after wire drawing are removed; the pickled workpiece is cleaned, and the cleaning time is 3 to 5 minutes; the workpiece is completely immersed into a phosphating solution, a phosphating filmis formed on the surface of the workpiece, and the phosphating time is 10 to 30 minutes; drying is conducted, the drying temperature is 110 to 120 DEG C, and the drying time is 30 minutes; electrostatic powder spraying is conducted, a zinc coating layer is formed on the surface of the workpiece, and the thickness of the coating layer is 60 to 80 [mu]m; and baking is conducted, the baking temperature is 180 to 200 DEG C, and the baking time is 30 minutes. Through the process, a layer of high-adhesion zinc coated anti-corrosion layer with high adhesion is formed on the surface of the stainless steel workpiece and is not likely to peel off, the brightness is low, and the problem of light pollution is solved.