A system for manufacturing a secondary battery, the system comprising: a positive electrode cell manufacturing line in which a positive electrode single cell, on which a tab is processed on one end of a positive electrode, and a separator is combined on one surface of the positive electrode, is continuously manufactured; a negative electrode cell manufacturing line in which a negative electrode single cell, on which a tab is processed on one end of a negative electrode, and a separator is combined on one surface of the negative electrode, is continuously manufactured; a stacking part alternately receiving the positive electrode single cells and the negative electrode single cells from the positive electrode cell manufacturing line and the negative electrode cell manufacturing line to stack the positive electrode single cells and the negative electrode single cells up to a predetermined layer, thereby forming a stack cell; a welding part in which primary welding is performed so that the negative electrode tabs of the stack cell transferred from the stacking part are connected to each other to form one tab, and the positive electrode tabs of the stack cell transferred from the stacking part are connected to each other to form one tab; and a packaging part in which the stack cell transferred from the welding part is put into a pouch, and the pouch is partially sealed, wherein the positive electrode cell manufacturing line and the negative electrode cell manufacturing line are connected in parallel to each other, and the stacking part, the welding part, and the packaging part are successively connected in series to each other to perform continuous processing. a positive electrode cell manufacturing line in which a positive electrode single cell, on which a tab is processed on one end of a positive electrode, and a separator is combined on one surface of the positive electrode, is continuously manufactured; a negative electrode cell manufacturing line in which a negative electrode single cell, on which a tab is processed on one end of a negative electrode, and a separator is combined on one surface of the negative electrode, is continuously manufactured; a stacking part alternately receiving the positive electrode single cells and the negative electrode single cells from the positive electrode cell manufacturing line and the negative electrode cell manufacturing line to stack the positive electrode single cells and the negative electrode single cells up to a predetermined layer, thereby forming a stack cell; a welding part in which primary welding is performed so that the negative electrode tabs of the stack cell transferred from the stacking part are connected to each other to form one tab, and the positive electrode tabs of the stack cell transferred from the stacking part are connected to each other to form one tab; and a packaging part in which the stack cell transferred from the welding part is put into a pouch, and the pouch is partially sealed, wherein the positive electrode cell manufacturing line and the negative electrode cell manufacturing line are connected in parallel to each other, and the stacking part, the welding part, and the packaging part are successively connected in series to each other to perform continuous processing.