Provided is a double-layer PCB, which comprises a first layer of board body and a second layer of board body. The first layer of board body is provided with a first via hole; the second layer of board body is provided with a second via hole in the place corresponding to the first via hole; the joint place between the first via hole and the second via hole is provided with a hysteresis tin portion, the diameter of which is larger than that of the first via hole and the second via hole; the hysteresis tin portion is at least internally provided with a plane portion having a conductive material; and the plane where the plane portion locates is parallel to the surface of the first layer of board body. The double-layer PCB has the advantages of low virtual welding rate during wave-soldering process and high welding stability.