The utility model relates to a current transformer metal expander oil valve, in particular to a current transformer metal expander multifunctional oil injection valve which comprises a connection base. The connection base is arranged to be a hollow pipe, a top cap is arranged at the top, the middle of the connection base is communicated with a connector connected with a distributor, a fastening screw is arranged in the connection base, the fastening screw is arranged to be of an integrated structure, a cylinder with a horizontal cutter groove formed in the middle is arranged on the upper portion of the fastening screw, the diameter of the middle of the fastening screw is smaller than that of the cylinder on the upper portion of the screw, and a rectangular protrusion is arranged on the lower portion of the fastening screw at the position corresponding to the horizontal cutter groove. The valve is simple in structure and convenient to use, vacuumizing and oil injection are finished under the condition that a pipeline is not disassembled, the vacuumizing and the oil injection are conducted in a split mode through a distributor, the vacuum state in the device is ensured, the sealing performance in the oil injection process is ensured, the fastening screw is utilized to adjust the position of a sealing screw of the metal expander oil injection valve, the disassembly trouble is saved, and the working efficiency is greatly improved.