When vertical roller mill is broken and running with load, the locking failure is caused by the pressure loss of the hydraulic station, and the adjusting sleeve will rotate with vertical roller mill. If the operator does not find and deal with it in time, it will cause the adjusting sleeve to be stuck, which will lead to the vertical roller mill and shutdown.The causes of adjusting sleeve sticking may also be poor thread lubrication, wear of adjusting cap seal or dust cover seal, scratch of adjusting sleeve and support sleeve thread, or vertical roller mill, long time overload work, etc.