The present disclosure provides a secondary battery which comprises a cap plate, an electrode assembly and a first connecting piece. The cap plate comprises a first electrode terminal; the electrode assembly comprises a main body, a first electrode tab; the first connecting piece is connected between the first electrode tab and the first electrode terminal. The first electrode tab includes a first connecting portion provided below the first connecting piece and a first bending portion connecting the main body and the first connecting portion. The secondary battery further comprises a first protecting piece fixed to a bottom of the first connecting portion. The first protecting piece includes a main portion and a first curve portion connected with an outer end of the main portion and curved relative to the main portion; the first bending portion is bent downwardly along a curved outer wall of the first curve portion.