A secondary battery and an electrode plate are provided. The electrode plate includes a current collector, an active material layer, a conductive structure, and a first protective layer. The current collector includes an insulating layer and a conductive layer disposed on the insulating layer. The conductive layer includes a main body portion and a protrusion portion. A surface of the main body portion facing away from the insulating layer is covered by the active material layer, while a surface of the protrusion portion facing away from the insulating layer is uncovered by the active material layer. The conductive structure is welded to the protrusion portion and thus a welded zone is formed. The first protective layer has elasticity, and is disposed on a side of the protrusion portion facing away from the insulating layer and is located between the welded zone and the active material layer.