Method for welding heat exchanger tube plate and welding joint of heat exchange tube

The invention relates to a method for welding a heat exchanger tube plate and a welding joint of a heat exchange tube. During assembling of the heat exchange tube and the tube plate, a structure which is sunken into the surface of the tube plate 0.5 to 1 millimeter is adopted; during welding, a welding sequence from bottom to top is adopted, and a 3-shaped or S-shaped welding running line is adopted; during welding, each heat exchange tube is welded with a half of a cycle, and after 8 to 10 heat exchange tubes are welded disposably without arc quenching, the tube plate is subjected to the arc quenching; and according to the same method, the other half of the cycle is welded from bottom to top. Therefore, the frequency of arc stopping and arc starting can be reduced, the welding efficiency is improved, and the number of arc starting and stopping points and the probability of generating welding defects can be reduced. During welding, a tungsten electrode can be stretched into the root part of an included angle