The invention relates to a flame preheating tungsten electrode argon arc brazing method used for austenitic stainless steel brazing and connection. The method includes the following steps that multiple pieces of stainless steel parent metal are in butt joint, the brazing seam gap width ranges from 0.05 mm to 0.5 mm, brazing filler metal is prearranged above brazing seams, gaps can be filled with the brazing filler metal, and the gaps of the brazing seams and brazing filler metal welding wires are covered with brazing flux; the surfaces of the pieces of parent metal far away from the brazing seams are preheated through flame guns, and the brazing flux is melted through heat transfer; and after the brazing flux is completely melted, argon tungsten-arc welding guns are used for conducting arc discharge to heat the brazing filler metal wires quickly, gaps of the parent metal are filled with the melted brazing filler metal, and the parent metal is baked through flames in the cooling process to prevent the parent metal from being cooled too quickly or cooled at uneven temperatures. The flame preheating tungsten electrode argon arc brazing method has the beneficial effects that the problems that thermal stress and thermal deformation are serious and interfaces are prone to cracking when austenitic stainless steel is directly brazed in an argon arc manner are solved, and brazing joints high in density, high in brazed rate and small in deformation can be obtained.