The present disclosure provides a secondary battery which comprises: a cap plate provided with a first electrode terminal; an electrode assembly comprising a main body and a first electrode tab; a first connecting piece connected between the first electrode tab and the first 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 arranged on the first connecting piece to prevent direct physical contact between the first electrode tab and the first electrode terminal connecting portion by covering at least an edge of the first electrode terminal connecting portion.