A CO2 laser-metal active gas welding (MAG) hybrid welding technology is used to weld the high strength steel of 7.0 mm thick. The effect of the arc energy, laser energy and distance between laser and MAG arc on the droplet transfer character, process stable and weld geometry are investigated. Results indicate that inputting of laser decreases the resistance of plasma channels of locate laser keyhole. In this way, arc is attracted and constricted, which stabilizes the arc cathode spots. The arc energy determines the mode of droplet transfer, and the laser energy affects the frequency of droplet transfer. When the laser energy is less than 4 kW, the transfer mode is short circuit transfer, or globular transfer or transfer mode between short circuit and globular. When laser energy exceeds 4.68 kW, the transfer mode is spray transfer. The droplet transfer mode is very important for achieving a stable and repeatable process: projected/spray transfer should be preferred to short/globular transfer. Distance between laser and arc sources must be at a 2～4 mm in order to avoid turbulence in the weld pool and disturbance of the keyhole formation and to achieve synergy between the processes.