The invention discloses a confluence welding belt welding machine which comprises a rack. A work tabletop is arranged on the rack, a long welding belt discharging mechanism, a long welding belt shearing mechanism and a long welding belt pulling mechanism which are sequentially arranged are included, wherein a long welding belt carrying mechanism is arranged on one side of the long welding belt pulling mechanism; a short welding belt discharging mechanism, a short welding belt shearing mechanism and a short welding belt pulling mechanism which are sequentially arranged are further included, wherein a short welding belt carrying mechanism is arranged on one side of the short welding belt bending pulling mechanism; and a welding mechanism arranged between the long welding belt carrying mechanism and the short welding belt carrying mechanism is further included. When the long welding belt carrying mechanism and the short welding belt carrying mechanism carry a long welding belt and a short welding belt to the position below a welding mechanism correspondingly, one end of the long welding belt and one end of the short welding belt are stacked, and the long welding belt and the short welding belt form an L shape. The confluence welding belt welding machine can be used for conducting full-automatic operation of shearing, carrying and welding, the welding position is accurate, unnecessary working links are saved, time and labor are saved, and the production efficiency is improved.