The semi-automatic longitudinal seam welding machine is designed for efficient welding of steel drum body seams in medium-scale drum manufacturing applications. It combines manual loading with automated welding movement and parameter control, providing a practical balance between production efficiency and operational flexibility. The machine uses resistance seam welding technology to create continuous and uniform welds along the drum body. Welding current, pressure, speed, and other parameters can be adjusted according to different steel materials and drum specifications, helping achieve stable welding quality and reliable seam strength. Suitable for 200L steel drums, chemical barrels, oil drums, and industrial metal containers, the equipment features a compact structure, convenient operation, and relatively low investment requirements. It can be integrated with drum forming, flanging, ribbing, and sealing equipment, making it a suitable choice for manufacturers upgrading from manual production to a more efficient semi-automated steel drum production line.