The invention discloses a plate-strip rolling mill roll system vibration inhibiting system and method based on hydraulic cylinder control. An acceleration sensor (1) is arranged at the bottom of a hydraulic cylinder rigid body (3). A temperature sensor (2) is arranged on a side of the hydraulic cylinder rigid body (3). The hydraulic cylinder rigid body (3) is connected with a temperature adjuster (4). The temperature adjuster (4) is connected with a comprehensive control device (5). According to the invention, related technique for roller vertical vibration inhibition is realized through performing control over oil temperature of a hydraulic cylinder of a rolling mill screwdown gear and a rolling vibration inhibition closed-loop system combining hydraulic cylinder oil temperature and roll system vibration parameters are proposed based on theoretical study and field practice, help is provided for solving rolling mill vertical vibration problems. The system is simple in structure and can realize a rolling mill roll system vibration inhibiting device achieving mutual feedback adjustment of vibration and temperature conveniently and quickly.