The present disclosure provides a secondary battery which comprises: a cap plate provided with a first electrode terminal and a second electrode terminal; an electrode assembly comprising a main body, a first electrode tab and a second electrode tab; a first connecting piece connected between the first electrode tab and the first electrode terminal. The second electrode tab is electrically connected with the second electrode terminal. The first connecting piece includes a first electrode terminal connecting portion, a first electrode tab connecting portion and a first fusing portion. The secondary battery further comprises an insulating piece adhered on a surface of the first connecting piece which is connected with the first electrode tab, and the insulating piece at least covers an edge of the first electrode terminal connecting portion close to the first electrode tab, so as to isolate the first electrode tab from the first electrode terminal connecting portion.