Hot rolling mill is made of continuous casting slab or first rolled slab as raw material, which is heated by stepping furnace and dephosphorized by high pressure water after entering roughing mill. The roughing mill material is cut head, tail and then entered into finishing mill to implement computer controlled rolling. After final rolling, it passes through laminar cooling (computer controlled cooling rate) and coiling machine to become straight roll. The head and tail of straight hair roll are often tongue and fish tail, the thickness and width accuracy is poor, and the edge often has wave shape, hem, tower shape and other defects. After finishing the straight hair coil by cutting the head, cutting the tail, cutting the edge, straightening and leveling several times, then cutting the plate or rewinding, it becomes: hot rolled steel plate, flat hot rolled steel coil, slitting strip and other products. The hot rolled pickling plate roll is formed after removing the oxide skin by pickling and applying oil.