The invention relates to the field of furnace tube 
welding, in particular to an 
austenite furnace tube 
welding method. The method comprises the steps that two preprocessed 
austenite furnace tubes are assembled and connected in an abutting mode; a flux-cored wire is used as backing 
welding materials, preliminary welding is carried out on one face of the position where the two 
austenite furnace tubes are connected in the abutting mode, the flux-cored wire extends from a gap between the two austenite furnace tubes to the welding face, the welding face faces upwards, and preliminary welding is ended when a 
coating layer is formed on the welding face; a flux-cored wire is used as 
filling materials, secondary welding is carried out on the position where the two austenite furnace tubes are connected in the abutting mode, meanwhile, the abutting connection position is filled with 
argon for protection, one end of the flux-cored wire is placed on the other end face, opposite to the welding face where the preliminary welding is carried out, of the gap between the two austenite furnace tubes, the flux-cored wire is molten constantly until welding is completed. According to the austenite furnace tube welding method, inconvenience brought when furnace tube bottoming welding tubes are filled with 
argon for protection is omitted, 
argon is saved, working efficiency is improved, meanwhile, 
crystal corrosion is avoided, 
residual stress in the 
welding process is reduced, and hot cracks are prevented from being generated.