The disclosure discloses a solder strip applied to a shingled solar cell module, including a flat portion, and an upper cell slice connecting portion and a lower cell slice connecting portion located at two sides of the flat portion; a plurality of fine grid lines are arranged in parallel on front/back surfaces of lower/upper cell slices; cutting directions of the lower cell slice and the upper cell slice are parallel to the fine grid lines; the solder strip is arranged perpendicular to the fine grid lines or parallel to busbars; and the upper cell slice partially overlaps with the lower cell slice, the flat portion is soldered to the fine grid lines/busbars on the front surface of the lower cell slice and the fine grid lines/busbars on the back surface of the upper cell slice to form an overlapped region, the upper cell slice connecting portion is soldered to the fine grid lines/busbars on the back surface of the upper cell slice, and the lower cell slice connecting portion is soldered to the fine grid lines/busbars on the front surface of the lower cell slice. The disclosure reduces a stress of a soldering point on a shingled solar cell of a MBB shingled solar cell module or a Smartwire shingled solar cell module under loading and temperature stresses, so that MBB and Smartwire technologies can be applied to the shingled solar cell module.