Production method for controlling thickness of scale of free-cutting steel

The invention discloses a production method for controlling the thickness of a free-cutting steel oxide scale. The production method comprises the following process steps: molten iron pretreatment, converter steelmaking, CAS treatment, LF external refining, continuous casting, heating in a heating furnace, rolling, controlled cooling, coil collection and finished product inspection. The composition and thickness of the oxide scale on the surface of the free-cutting steel wire are controlled by controlling the spinning temperature, the cooling speed after rolling and the like, the spinning temperature is guaranteed to be 860 DEG C or below by adjusting the water amount of a water tank behind a finishing mill, Fe2O3 red rust is generated on the surface of the wire, and the situation that the proportion of Fe3O4 in the oxide scale on the surface of a wire rod is increased due to the too high spinning temperature is avoided. By controlling the spinning temperature, the cooling speed after rolling and other proces