The height of the guide roll is 300mm~45mm, and it is used for the entrance of the rolling mill for rough rolling, intermediate rolling and pre-finishing rolling of rods and wires. "Compression spring + adjusting screw" adjusts the opening and closing of the support arm, thereby adjusting the opening degree of a pair of guide rollers. Guide roller bearings are lubricated with oil, gas or grease. There is a cooling water pipe next to the guide roller, which sprays water directly to cool the guide roller. The cooling water structure is simple and practical. Both the box body and the support arm are thick and have high strength.