A current collector for electrically connecting a pole post and a pole tab of a secondary battery, and the current collector comprising: a first sheet; a second sheet intersecting with the first sheet and to be electrically connected with the pole post; a current collecting unit, wherein the current collecting unit and the second sheet are respectively arranged on two opposite sides of the first sheet along its first thickness direction, the first thickness direction intersects with a second thickness direction of the second sheet itself, the current collecting unit comprises a first current collecting sheet to be electrically connected with the pole tab and comprising a first connection end connected with the first sheet, and the first connection end extends in a first direction perpendicular to the first thickness direction and the second thickness direction, wherein the current collecting unit further comprises a second current collecting sheet, the first current collecting sheet and the second current collecting sheet are disposed to be spaced apart along the second thickness direction, the second current collecting sheet is used to be electrically connected with the pole tab and comprises a second connection end connected to the first sheet, and the second connection end extends along the first direction, the first sheet comprises a main body connected to the second sheet and extending in the second thickness direction and a first outer extension connected to the main body, the first outer extension extends towards an outside of the main body along the first direction, and at least one of the first current collecting sheet and the second current collecting sheet is connected to the first outer extension, both the first current collecting sheet and the second current collecting sheet extend towards one side of the first sheet in the first thickness direction, and both can be folded in the first thickness direction, the thickness direction of the first current collecting sheet and the second current collecting sheet is the same as the second thickness direction of the second sheet before folding, and the directions (X, Y, Z) represent a three-dimensional Cartesian coordinate system. a first sheet; a second sheet intersecting with the first sheet and to be electrically connected with the pole post; a current collecting unit, wherein the current collecting unit and the second sheet are respectively arranged on two opposite sides of the first sheet along its first thickness direction, the first thickness direction intersects with a second thickness direction of the second sheet itself, the current collecting unit comprises a first current collecting sheet to be electrically connected with the pole tab and comprising a first connection end connected with the first sheet, and the first connection end extends in a first direction perpendicular to the first thickness direction and the second thickness direction, wherein the current collecting unit further comprises a second current collecting sheet, the first current collecting sheet and the second current collecting sheet are disposed to be spaced apart along the second thickness direction, the second current collecting sheet is used to be electrically connected with the pole tab and comprises a second connection end connected to the first sheet, and the second connection end extends along the first direction, the first sheet comprises a main body connected to the second sheet and extending in the second thickness direction and a first outer extension connected to the main body, the first outer extension extends towards an outside of the main body along the first direction, and at least one of the first current collecting sheet and the second current collecting sheet is connected to the first outer extension, both the first current collecting sheet and the second current collecting sheet extend towards one side of the first sheet in the first thickness direction, and both can be folded in the first thickness direction, the thickness direction of the first current collecting sheet and the second current collecting sheet is the same as the second thickness direction of the second sheet before folding, and the directions (X, Y, Z) represent a three-dimensional Cartesian coordinate system.