Abstract: Experiments were conducted to research the mutual effect,the interaction of laser and MIG arc and the influence of the addition of laser on the form of MIG arc and the type of metal transfer. The YAG laser and pulsed MIG hybrid welding system was established. In addition,high-speed photography system was used to observe the arc behavior and metal transfer, with the current signals and voltage signals of the arc collected synchronously. It was found that the metal transfer mode changed from one droplet per pulse to one droplet every two pulses with the addition of laser to MIG welding. Pulsed MIG arc could be apparently attracted by laser. The decrease of the vertical-force component of plasma force which could promote metal transfer was the main reason that caused the decline of the frequency of metal transfer.