Abstract: The influence of the pulsed MIG(metal inert gas) welding parameters on visual sensing effects in aluminum alloy welding process was investigated by using designed CCD visual sensing system. By altering the welding parameters, the influence of welding current mode, metal droplet transfer mode and arc length on visual sensing effects were studied. The results show that the metal droplet transfer mode has great influence on the visual sensing effects and other parameters also have important influence on the visual sensing effects.Under the suitable welding current mode and small drop transfer mode, good weld appearance and satisfying visual sensing effects are realized with the short arc.