Cathode protection device of steel water tank

The utility model relates to a water tank corrosion resistant protection device, in particular to a cathode protection device of a steel water tank. The technical scheme is that the cathode protection device of the steel water tank is composed of a water tank, a magnesium alloy anode, a screw and a spring gasket. The screw is fixed inside the water tank, the screw and the magnesium alloy anode are connected through threads, the spring gasket is arranged between the screw and the magnesium alloy anode, and a metal coating is painted on the inner surface of the water tank. The cathode protection device of the steel water tank has the advantages that corrosion prevention property is improved greatly, service life is long, scale is loose and easy to remove, the magnesium alloy anode is convenient to assemble and disassemble and can be changed regularly, and equipment can be repeatedly used.