The causes of hydraulic cylinder block tension vertical roller mill are as follows: One is that there are impurities in the hydraulic oil, which leads to the cylinder block being damaged and the seal is damaged and oil leakage occurs; Second, due to the top falling, fine particles are sandwiched between the hydraulic cylinder and piston rod, the chrome coating on the piston rod surface causes longitudinal draw marks due to wear, and the oil seal is damaged, resulting in oil leakage; Third, because the valve handle of the accumulator check valve is broken, bolts and washers enter the hydraulic cylinder, resulting in longitudinal pull marks, and the piston ring is pulled, which leads to the hydraulic cylinder block being damaged or the outer oil leakage is caused;