The effect of laser wavelength on the droplet transition behaviors is studied in the laser-CMT hybrid welding process. The results show that, the droplet transfer process is influenced when the molten pool shape and wire-heating are changed by the laser, and the laser-CMT hybrid welding process is more stable than the CMT welding process. The CO2 laser has a relatively strong influence on the droplet volume. When the CO2 laser power is relatively low, the laser can promote the droplet transition. However, the laser prevents the droplet transition process when the laser power increases. The fiber laser has a less effect on the wire-heating, but can increase the transition frequency of droplets. The plasma temperatures from the CO2 laser and fiber laser increase with the increase of the laser power. The plasma by the CO2 laser presents a lump-like eruption but that by the fiber laser shows no eruption.