A CO2 laser-metal active gas (MAG) hybrid welding is used to weld the high strength steel of 5.0 mm thickness. Droplet transfer is observed with high speed camera and the forces on droplet are investigated in detail. The droplet transfer is strongly affected by laser power, arc power and the distance between laser and arc. The results indicate that laser could make arc plasma more stable and decrease the critical current of spray transfer for its leading and constricting felnctions on the arc by the laser. There are changes in the current distribution within droplet and the magnitude and direction of electromagnetic force. At the same time, a large number of metal gas from the keyhole makes a metal steam reaction, changing the force state of the droplet so that the droplet transfer mode is changed. With the increase of the welding current, the arc becomes more stable and the power of arc is more concentrated, making the plasma drag force decisive. The distance between laser and arc has an effect on the frequency of the droplet transfer. When the distance is 4 mm, the frequency of the droplet transfer is the maximum.