The present disclosure provides a secondary battery and an electrode plate thereof. The electrode member comprises an insulating substrate, a first conducting layer and an active material layer; the first conducting layer is provided on a surface of the insulating substrate, the active material layer is provided at a side of the first conducting layer away from the insulating substrate; the first conducting layer is provided with a stripe-shape groove extending in a height direction, the stripe-shape groove is used for releasing stress of the first conducting layer. The secondary battery comprises an electrode assembly, the electrode assembly comprises the electrode member.