The hot-wire TIG welding equipment was built based on the heat-conduction method.The temperature-controlling model was developed and verified within a certain temperature range.The results showed that the wire temperature could be maintained at（220 ±5）℃.The comparing experiments between the hot-wire TIG at temperature of 220 ℃ and ordinary TIG were conducted.The results showed that the hot-wire TIG based on the heat-conduction method could improve the appearance and the feeding speed.When the appearance was similar,due to the chilling effect of hot wire TIG welding wire on arc is small,the efficiency of hot-wire TIG in bottom welding was doubled compared with that of the ordinary TIG.The efficiency of hot-wire TIG in cover welding was tripled compared with that of the ordinary TIG.Moreover,the microstructure of welding seam of the hot-wire TIG welding was finer than that of the ordinary TIG welding.The hardness of welding seam of the hot-wire TIG welding was harder than that of the ordinary TIG welding slightly.The mechanical property of the two joints was well.The fracture was located in the ASTM A106 base metal.