The invention discloses a full-automatic vertical position welding method for battery welding and a fixture device. The method comprises the following steps: S1) a battery to be welded is carried to an automatic welding station by a battery welding production line, and is put in a battery mold sleeve by a manipulator; S2) the battery in the battery mold sleeve is ejected to a position of an upper positioning pressure head by an upper push cylinder; a long edge pressing cylinder is forwards pushed to press the long edge of the battery; and a short edge pressing cylinder is forwards pushed to press the short edge of the battery; S3) a laser welding worktable moves to the position of the battery to be welded; and a laser probe begins to weld; and S4) the laser welding worktable leaves from the position of the battery to be welded, and releases each cylinder; and the manipulator takes out the welded battery from the battery mold sleeve. The method and the device need no turnover procedure and manual intervention and transfer, and greatly improve the battery welding efficiency, reliability and pass percent.