Abstract: A new welding method-arc-laser spot welding, based on the study of the interaction of arc and laser dual power source, is proposed in this paper. Experiments have proved that this new method can weld the joints which are difficult to be welded by ordinary spot welding. For instance, it can spot weld the lap joints of thicker upper plates with large plate thickness ratio as well as joints made up of copper, aluminum and other highly conductive materials.