The utility model relates to a special profile welding device for batteries, which comprises a horizontal base, a vertical supporting rod, a profiling mould fixing beam, a profiling mould, a rotating arm, a profiling arm and a welding gun. The vertical supporting rod is vertically and fixedly mounted on the horizontal base, one end of the profiling mould fixing beam is fixedly installed on the upper portion of the vertical supporting rod, the other end of the profiling mould fixing beam is fixedly mounted with the profiling mould, the middle portion of the rotating arm is installed on the vertical supporting rod below the profiling mould fixing beam through a shaft sleeve, one end of the profiling arm is hinged to one end of the rotating arm, a joint shaft is fixedly mounted at the other end of the profiling arm in vertical direction, the joint shaft is driven by a motor fixedly mounted at the lower end of the joint shaft, the upper end of the joint shaft is mutually engaged with the profiling mould to run, and the welding gun is fixedly mounted on the lower portion of the profiling arm corresponding to the joint shaft through a profiling insulator. The special profile welding device for the batteries can effectively increase welding quality of the batteries, shorten welding time, improve production efficiency of the batteries, and has comparatively fine welding coherence.