Once the vertical roller mill is in an abnormal operating state, it will also have an adverse effect on the use of the liner. Generally speaking, the steel ball and the material in the vertical roller mill are mixed together, so when the steel ball impacts the liner in a parabolic state, the material will play a certain buffer effect and gradually grind the material fine. When the equipment is running under low load, the steel ball will directly impact the liner, causing serious wear and even breakage of the liner.The working principle of the vertical roller mill is to use the cylinder to rotate, and according to the actual needs of the operation, the steel ball is raised to a certain height and then falls in a parabola, impacting the material in the cylinder, so that the material and the liner are fully rubbed. Therefore, under continuous work, the steel ball and the liner will be severely worn, which is directly related to the hardness of the material.