There are three methods to detect the thickness of zinc layer of galvanized wire: weighing method, cross section microscopy method and magnetic method, among which the first two experiments will cause certain damage to galvanized wire, including the length of galvanized wire and the reduction of dosage. The general detection of galvanized wire galvanized layer is detected by magnetic method, which is also a more intuitive and convenient method. The standard of galvanized layer thickness is related to the wire diameter of galvanized wire. The larger the wire diameter of galvanized wire, the thicker the galvanized layer is. It is the thickness of galvanized layer and cast iron after centrifugal separation.