Finned tube heat exchanger is a special equipment for gas-water, gas-steam and other heat transfer conditions (on both sides of the medium heat transfer coefficient difference, operating pressure difference). The steam/water goes inside the tube, and the atmospheric gas goes outside the tube. The high frequency welding bolt wing-around processing technology is adopted outside the tube to significantly expand the heat transfer area outside the tube, so as to balance the heat transfer capacity on both sides. Compared with the light tube, its economy and investment cost has a good advantage.