Welding wire diameter detector

The utility model relates to the technical field of welding wire detection, and discloses a welding wire diameter detector which comprises a machine body, the top of the machine body is respectively provided with a positioning device and a conveying roller, the positioning device is internally provided with a cylinder, the front face and the back face of the machine body are respectively provided with a fixing device, and the conveying roller is arranged on the machine body. A collecting device is arranged on the side, away from the positioning device, of the surface of the machine body. According to the welding wire diameter detector, the cylinder with the standard diameter is placed in the groove, the moving block fixes the cylinder, a welding wire needing to be detected penetrates through the cylinder, when the diameter of the welding wire is unqualified, the welding wire cannot penetrate through the cylinder, the inductor induces that the welding wire of the corresponding cylinder stops moving, and an ala