Abstract: A test system for multi-gas shielded high-current MAG welding is developed which includes and one-knob controlled IGBT inverter power supply, a dual-driver wire feeder with armature potential and speed feedback signal control, a dual circuit water cooling torch and a gases mixing supply unit with precise mass flow control. The system is characterized by fast response of power supply, stable speed of wire feeding with wide range of speed regulation and accurate gases supply. With the system, the deposition rate is twice as that with common MAG welding system, that make high-current MAG welding with φ 1.2mm wires possible.