Annular cooling pipe joint welding tool and welding method

The invention discloses an annular cooling pipe joint welding tool and a welding method.The welding tool comprises a bottom frame, a plurality of fixing assemblies are evenly arranged on the bottom frame at intervals, the fixing assemblies are used for fixing cooling pipes during welding, and each fixing assembly comprises vertical frames installed on the two sides of the bottom frame; supporting pieces used for supporting the cooling pipe are arranged on the top and in the middle of the vertical frame, a fixing plate is arranged in front of the supporting pieces, and the fixing plate is connected with the supporting pieces through bolts and used for supporting and fixing the cooling pipe. The special welding tool is used for the copper pipe and stainless steel pipe joint brazing process, it is ensured that a brazed workpiece is in a vacuum condition, the phenomena of oxidation, recarburization, decarburization, pollution deterioration and the like are avoided, the surface quality of the copper pipe and the p