Abstract: A high-speed flat cable having a better bending/folding memory and a manufacturing method thereof are provided. The high-speed flat cable includes a plurality of shielded signal units, one or more bendable composite layers, and an adhesive layer. The shielded signal units are substantially coplanar, spaced apart from each other or adjoining each other. The one or more bendable composite layers includes an inner insulating film layer, a bendable aluminum foil layer, and an outer insulating film layer. The one or more bendable composite layers composed of the inner insulating film layer, the bendable aluminum foil layer, and the outer insulating film layer increase its mechanical bending/folding property to improve the bending/folding memory. The one or more bendable composite layers allow the flat cable to be bent with ease without rebounding, thereby enhancing production efficiency.