Abstract: This paper evaluated the appearance characteristics of YAG laser+CMT arc hybrid horizontal welding on 304 stainless steel by the welding appearance parameters.The influence of welding parameters on weld appearance during Nd:YAG laser+CMT arc hybrid horizontal welding were studied.Compared with CMT welding,the influence of welding parameters on weld appearance during Nd:YAG laser+CMT arc hybrid horizontal welding were analyzed.The results indicated that hybrid weld appearance could be improved by adding laser during CMT arc welding.There was an optimum spacing of light wire matched to form the best weld appearance during Nd:YAG laser+CMT arc hybrid horizontal welding when the laser power and welding current was constant.The impact of laser power on the penetration depth was greater than the other hybrid welding.The influence on weld appearance was relevant to the welding current;the effect of welding speed on weld appearance was great while the effect of defocus amount on weld appearance was small.There was a great influence of weld power on the offset of horizontal weld.