Abstract: The short-circuit transfer of CO₂ gas shielded arc welding is widely used in manufacturing industry, but there are many problems such as spatter, poor formation,unstable transition, etc. in this welding process, especially during higher welding current. A new approach to solve the problems were put forward through applying a synchronous magnetic field. The effect of the synchronous magnetic field with different types on arcing phase was investigated. The short-circuit transfer processes were captured through high-speed camera system with laser backlight to observe the droplet transfer process, calculate droplet size and transfer frequency, etc. The experimental results showed that the droplet transfer frequency was increased, the short-circuit metal transfer process was more stable, the shape of droplet was changed evidently from a round or ellipsoid with sharp tip to flat end, and the dimension of droplet was reduced.