A vertical vibration model of a 3-DOF strip rolling mill with a compound roll bearing failure on the outer raceway and inner raceway is established. Through MATLAB simulation, the vertical vibration characteristics of the strip mill work roll are compared and analyzed under the condition that the outer raceway failure of the roller bearing remains unchanged, the inner raceway failure changes and the inner and outer raceway failures change simultaneously. It provides a certain theoretical basis for further clarifying the non-linear vibration mechanism of the rolling mill caused by the compound bearing failure. At the same time, when the internal and external raceways of the roller bearing have a compound failure, the effects of different roller numbers and contact angles on the vibration displacement fluctuations of the work roll are analyzed, which has certain theoretical guidance for the optimization design of the roll bearing.