A secondary battery, comprising: a cap plate provided with a first electrode terminal and a second electrode terminal; an electrode assembly comprising 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 being 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 first electrode terminal connecting portion is fixed to the first electrode terminal, the first electrode tab connecting portion is fixed to the first electrode tab, and the first fusing portion is connected between the first electrode terminal connecting portion and the first electrode tab connecting portion; the secondary battery further comprises an insulating holding block, two ends of the insulating holding block are connected with the first electrode terminal connecting portion and the first electrode tab connecting portion respectively, and the insulating holding block is configured to maintain the first electrode terminal connecting portion and the first electrode tab connecting portion in position relative to each other when the first fusing portion is fused; each of the first electrode terminal connecting portion and the first electrode tab connecting portion is provided with a through fixing hole; the insulating holding block comprises a first holding portion and a second holding portion; the first holding portion is provided on one side of the first connecting piece along a thickness direction and includes fixing posts which respectively correspond to the fixing hole of the first electrode terminal connecting portion and the fixing hole of the first electrode tab connecting portion, and each fixing post passes through the fixing hole and extends to the other side of the first connecting piece along the thickness direction; the second holding portion is provided on the other side of the first connecting piece along the thickness direction and is connected with the fixing posts of the first holding portion which respectively pass through the fixing hole of the first electrode terminal connecting portion and the fixing hole of the first electrode tab connecting portion; wherein the second holding portion is connected with the fixing posts of the first holding portion by means of hot melting, interference fit, riveting, latching, adhering or inserting. a cap plate provided with a first electrode terminal and a second electrode terminal; an electrode assembly comprising 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 being 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 first electrode terminal connecting portion is fixed to the first electrode terminal, the first electrode tab connecting portion is fixed to the first electrode tab, and the first fusing portion is connected between the first electrode terminal connecting portion and the first electrode tab connecting portion; the secondary battery further comprises an insulating holding block, two ends of the insulating holding block are connected with the first electrode terminal connecting portion and the first electrode tab connecting portion respectively, and the insulating holding block is configured to maintain the first electrode terminal connecting portion and the first electrode tab connecting portion in position relative to each other when the first fusing portion is fused; each of the first electrode terminal connecting portion and the first electrode tab connecting portion is provided with a through fixing hole; the insulating holding block comprises a first holding portion and a second holding portion; the first holding portion is provided on one side of the first connecting piece along a thickness direction and includes fixing posts which respectively correspond to the fixing hole of the first electrode terminal connecting portion and the fixing hole of the first electrode tab connecting portion, and each fixing post passes through the fixing hole and extends to the other side of the first connecting piece along the thickness direction; the second holding portion is provided on the other side of the first connecting piece along the thickness direction and is connected with the fixing posts of the first holding portion which respectively pass through the fixing hole of the first electrode terminal connecting portion and the fixing hole of the first electrode tab connecting portion; wherein the second holding portion is connected with the fixing posts of the first holding portion by means of hot melting, interference fit, riveting, latching, adhering or inserting.