The utility model relates to an automatic submerged arc welding device for a circular seam in a container. The automatic submerged arc welding device is characterized by comprising a connecting plate (1), wherein a lengthened cantilever (2) is fixedly arranged on the connecting plate (1); a double-suspending lug hanging arm (3) is connected with the other end of the lengthened cantilever (2); a transition plate (4) is connected with the bottom end of the double-suspending lug hanging arm (3); a through hole is arranged at the bottom of the transition plate (4); a supporting shaft (5) is inserted into the through hole; a welding machine head is arranged on the supporting shaft (5); and a solder feeding mechanism is also arranged on the supporting shaft (5). The aspects of material section, structure design and mounting fixation are fully considered; the automatic submerged arc welding device is used together with a cantilever type welding operator; the structure is simple and the operation is convenient; the implementation of the automatic submerged arc welding for the circular seam in the container and an annular surfacing layer is realized; the welding quality is ensured; the production efficiency is increased by 2-3 times; and the personnel safety hidden danger problem under an airtight and high-temperature operating environment is solved.