Low power pulsed laser-MAG hybrid welding was carried out by different heat source arrangement methods (lead mode, distance between laser spot and welding wire tip (DLA)). The coupling effect and welding characteristics of hybrid heat sources under different modes were studied by using high speed image (HSI) and real-time electrical signals. HSI observation and electronic signals showed that the lead mode and DLA significantly affect the coupling state of heat source and welding characteristics (weld morphology, process stability and droplet transfer). The influence of lead mode on weld forming was more significant than that of DLA.In laser-lead mode, when DLA = 1~2mm, the laser and arc had perfect coupling effect, good weld formation, less spatter and greater penetration. In arc-lead mode, the weld formation was poor and undercut defects were common, while the overall penetration was greater than that in laser-lead mode. In terms of welding process stability, arc-lead mode was better than laser-lead mode. The pulsed laser increased the stability of projected transition, produced more fine droplets and reduced the generation of spatter. When DLA = 1~2mm, stable droplet transfer could be realized under both modes.