A portable four-in-one tool for a welder is a special tool used by welding workers. A cylinder is arranged at one end of a hammer, and an inclined surface is disposed at the other end of the hammer; a cylindrical handle is perpendicularly welded in the middle of the hammer, and a grip which is formed by means of bending round steel is welded at the other end of the handle; a large cuboid-shaped hammer wing and a small cuboid-shaped hammer wing are welded on the handle and can be used as a fixing wrench; a hexagon socket is welded in the middle of the hammer and positioned on another plane, which is opposite to the hammer, of the handle; and a rectangular notch is disposed on a side wall of the hammer. The portable four-in-one tool for the welder has the advantages that various tools which are used in metal welding and gas cutting procedures are integrated, the portable four-in-one tool is simple in structure and convenient in carrying, and is timesaving, work efficiency can be effectively improved, and production cost is lowered.