A weld overlay system includes a workpiece jig holding a workpiece in manner that the workpiece center axis direction is parallel to X-axis direction, and rotates the workpiece in circumferential direction, a carriage, welding base supported on the carriage in manner that the welding base is displaceable with respect to the carriage in Y-axis direction and Z-axis direction, at least one pair of rollers and welding torch are supported on the welding base, and like. Pair of rollers include rotary shafts extend in parallel with the X-axis and are spaced apart from each other in Y-axis direction. The rollers are pressed against portion of the workpiece above the workpiece center axis C. The welding torch is supported on the welding base in manner that distances in Y-axis direction from the rotary shafts of the pair of rollers to the tip end of the welding torch are equal to each other.