The utility model discloses a U-shaped bending tool, comprising a syphon mother matrix, a rolling extrusion head and a connecting sheet, which is characterized in that the rolling extrusion head can be rotated and positioned on the siphon mother matrix by one end of the connecting sheet; the rolling extrusion head can be rotated and fixed on the other end of the connecting sheet; the shape forming slot matching with the rolling extrusion head is positioned on the syphon mother matrix. The U-shaped bending tool has the advantages that the thin wall slim tube can be folded and bended into U-shaped tube accurately by the tool, and the convenience and high efficiency are guaranteed.