The disclosure relates to a secondary battery and a battery module. The secondary battery comprises: a case comprising a receiving hole having an opening; a cap assembly sealingly connected with the case to close the opening; an electrode assembly disposed in the receiving hole, wherein the electrode assembly comprises two end surfaces opposite to each other in a first direction perpendicular to an axial direction of the receiving hole and tabs extending from respective end surfaces, and the electrode assembly comprises two or more electrode units which are stacked in the axial direction; and a current collecting unit comprising a first sheet and a first current collecting sheet connected to the first sheet, wherein both the first sheet and the first current collecting sheet extend in the axial direction, and the tab is bent with respect to the first direction and is electrically connected to the first current collecting sheet.