A FPCB/FCCL replacing a tinned-copper welding strip as a photovoltaic module bus bar is a composite material including an insulating base material and a conductive layer, and the insulating base material is made from PI or PET, and the conductive layer is generally the copper foil. According to the present invention, when the flexible solar module adopts the FPCB/FCCL to replace the tinned-copper welding strip as the photovoltaic module bus bar, the product quality and product stability are greatly improved, and the FPCB/FCCL bus bar is also suitable for the double-glass solar module and the single-glass solar module. The copper foil of FPCB/FCCL may be integrated with circuits, or be the complete copper foil (without circuits), or the copper foil of FPCB/FCCL may simultaneously has the part with circuits and the part without circuits.