The invention discloses an anti-corrosion coating for cathode protection and a preparation method of the coating and belongs to the technical field of surface protection of high-voltage electrical equipment. The anti-corrosion coating comprises a Dacromet layer, a primer layer and a finish layer; compared with the single Dacromet layer or a composite coating comprising the Dacromet layer and the finish layer, the anti-corrosion coating has the excellent surface rust resistance and the excellent knocking and scratching resistance, the deficiencies that the Dacromet layer is soft and easy to knock and scratch can be made up, and the defect that a physical protection layer is poor in coating performance can be overcome. With the coating, cathode coating and physical protection are combined, and in the corrosion process, even if one protection form fails, the other protection form can make up the deficiencies of the failed protection form immediately, so that a base material is prevented from being corroded directly, and the probability of performance failure of a workpiece due to corrosion is greatly reduced. Meanwhile, the preparation technology of the anti-corrosion coating is simple, and the coating is convenient to operate and suitable for industrial production and application.