CO2 gas metal arc welding refers to a gas metal arc welding that takes carbon dioxide as the shielding gas and melts the metal through the arc generated between the welding wire and weldment. It is widely used in engineering machinery manufacturing, automotive industry, shipbuilding, locomotive manufacturing, boiler pressure vessel manufacturing, and other industries. This course mainly introduces the composition, function and operation of CO2 gas metal arc welding equipment and the selection and adjustment of welding process parameters and basic welding operation techniques.