A secondary battery, including a first terminal, a second terminal, a first electrode plate, a second electrode plate, a first connecting piece and a second connecting piece, the first terminal, the first connecting piece and the first electrode plate together form a current path, the second terminal, the second connecting piece and the second electrode plate together form a current path; At least one of the first and second connecting piece is provided with a fuse device which includes a first and a second fuse part, the first and second fuse part are connected in series to the current path where the fuse device is, the first and second fuse part respectively has a smaller cross-sectional area than that of adjacent domains, the first and second fuse part are spaced from each other, and the first fuse part has the same cross-sectional area as the second fuse part does.