The effects of welding mode, laser-wire distance, energy input on droplet transfer behavior and the weld porosity defects are studied by laser-MAG hybrid welding process of edge joint. The research results show that laser-MAG hybrid welding is more suitable for the edge joint because of the improvement of weld formation and inhabitation of porosity. Laser leading mode is better than arc leading mode for the less weld porosity. A large distance of laser-wire is beneficial for the stability of welding process. The arc energy input mainly affects the weld formation, while the increase of laser power prevents droplet transfer and increases porosity defects at the bottom of the weld.