Disclosed are a method and device for welding and converging battery cell tabs, which is used for welding and converging battery core end faces. The method comprises: laminating to form a plate set composed of a positive plate, a separator and a negative plate by laminating, the positive plate comprising a positive tab, and the negative plate comprising a negative tab; during laminating, bending the positive tab to form a positive tab bend, and bending the negative tab to form a negative tab bend; and welding the positive tab bend of each positive plate in the plate set, and/or welding the negative tab bend of each negative plate in the plate set. Based on the method and device, a reserved length of the tab is reduced, and a material loss of the tab material is greatly reduced. Station circulation is reduced and production efficiency and a product yield are improved.