The invention relates to a steel wire galvanization thickness control device and method which are used for controlling the steel wire galvanization thickness during hot-dip galvanization, and belongs to the technical field of steel wire hot-dip galvanization. The device comprises a galvanizing tank, and a galvanizing zinc pool which is located below the galvanizing tank and connected with the galvanizing tank through two pipes. A liquid level sensor is arranged in the galvanizing tank and connected with a PLC control system. The liquid level condition, of galvanizing zinc in the galvanizing tank, obtained through the liquid level sensor is used for controlling a circulating pump located between the galvanizing tank and the galvanizing zinc pool through the PLC control system, so that the galvanizing zinc amount in the galvanizing tank is regulated and controlled, and accordingly the immersing distances of steel wires in the galvanizing zinc of the galvanizing tank are guaranteed to be the same. By adoption of the steel wire galvanization thickness control device and method, the galvanizing zinc amount in the galvanizing tank can be monitored, regulated and controlled in real time, and the thicknesses of zinc layers in the steel wire hot-dip galvanization process can be controlled in real time.