This course mainly introduces the manual tungsten inert gas welding equipment models, and the functions and use of the buttons on the control panel. Moreover, it takes an example of a V-shaped groove of an 8 mm steel plate that is welded only on a single face and formed on both sides. The welding steps include workpiece processing and tool preparation, workpiece leveling, degreasing and rust removal, and spot welding. The welding layers are those by backing welding, filler welding, and cosmetic welding. Welding process parameters must be chosen and adjusted in a correct way. In welding, attention must be paid to the way to swing the arc welding gun and add the welding wire to avoid welding defects.