A device for welding and converging battery cell tabs, characterized in that, comprising: a laminating station for forming a plate set composed of a positive plate, a separator and a negative plate by laminating, wherein the positive plate comprises a positive tab, and the negative plate comprises a negative tab; a mould pressing mechanism for bending the positive tab to form a positive tab bend; and/or, bending the negative tab to form a negative tab bend, wherein the positive tab bend has a straight section and a bent section, the straight section is formed by extending the positive plate, and the bent section is used for forming the positive tab bend; and the negative tab bend has a straight section and a bent section, the straight section is formed by extending the negative plate, and the bent section is used for forming the negative tab bend; a converging member for converging the plate sets, wherein a plurality of positive tabs of the plurality of plate sets are laminated to form a bent book page-shaped structure, a stress is provided between adjacent positive tab bends in the bent book page-shaped structure, and the bent book page-shaped structure forms a stressed entirety under actions of the stress and an elastic force generated by deformation of the plurality of positive tabs; and/or, a plurality of negative tabs of the plurality of plate sets are laminated to form a bent book page-shaped structure, a stress is provided between adjacent negative tab bends in the bent book page-shaped structure, and the bent book page-shaped structure forms a stressed entirety under actions of the stress and an elastic force generated by deformation of the plurality of negative tabs; and, a welding assembly for welding a plurality of positive tab bends in the plate sets, wherein the welded positive tab bends are directly welded to a cell case; and/or, welding a plurality of negative tab bends in the plate sets, wherein the welded negative tab bends are directly welded to the cell case; wherein the converging member has a C-shaped structure, and the plate sets are transferred to the converging member along a side opening of the C-shaped structure, or, the converging member has a U-shaped structure, and the plate sets are transferred to the converging member along an upper opening of the U-shaped structure. a laminating station for forming a plate set composed of a positive plate, a separator and a negative plate by laminating, wherein the positive plate comprises a positive tab, and the negative plate comprises a negative tab; a mould pressing mechanism for bending the positive tab to form a positive tab bend; and/or, bending the negative tab to form a negative tab bend, wherein the positive tab bend has a straight section and a bent section, the straight section is formed by extending the positive plate, and the bent section is used for forming the positive tab bend; and the negative tab bend has a straight section and a bent section, the straight section is formed by extending the negative plate, and the bent section is used for forming the negative tab bend; a converging member for converging the plate sets, wherein a plurality of positive tabs of the plurality of plate sets are laminated to form a bent book page-shaped structure, a stress is provided between adjacent positive tab bends in the bent book page-shaped structure, and the bent book page-shaped structure forms a stressed entirety under actions of the stress and an elastic force generated by deformation of the plurality of positive tabs; and/or, a plurality of negative tabs of the plurality of plate sets are laminated to form a bent book page-shaped structure, a stress is provided between adjacent negative tab bends in the bent book page-shaped structure, and the bent book page-shaped structure forms a stressed entirety under actions of the stress and an elastic force generated by deformation of the plurality of negative tabs; and, a welding assembly for welding a plurality of positive tab bends in the plate sets, wherein the welded positive tab bends are directly welded to a cell case; and/or, welding a plurality of negative tab bends in the plate sets, wherein the welded negative tab bends are directly welded to the cell case; wherein the converging member has a C-shaped structure, and the plate sets are transferred to the converging member along a side opening of the C-shaped structure, or, the converging member has a U-shaped structure, and the plate sets are transferred to the converging member along an upper opening of the U-shaped structure.